U.S. patent application number 09/875995 was filed with the patent office on 2001-10-25 for method for producing long-chain glycine-n,n-diacetic acid derivatives.
This patent application is currently assigned to BASF AKTIENGESELLSCHAFT. Invention is credited to Braun, Gerold, Detering, Juergen, Greindl, Thomas, Oetter, Guenter, Oftring, Alfred, Rahm, Rainer.
Application Number | 20010034457 09/875995 |
Document ID | / |
Family ID | 7839779 |
Filed Date | 2001-10-25 |
United States Patent
Application |
20010034457 |
Kind Code |
A1 |
Rahm, Rainer ; et
al. |
October 25, 2001 |
Method for producing long-chain glycine-N,N-diacetic acid
derivatives
Abstract
A process for preparing compounds of the formula IIb 1 where R
is C.sub.6-C.sub.30-alkyl or C.sub.6-C.sub.30-alkenyl, which may
additionally have upto 5 hydroxyl groups, formyl groups,
C.sub.1-C.sub.4-alkoxy groups, phenoxy groups or
C.sub.1-C.sub.4-alkoxyca- rbonyl groups as substituents and may be
interrupted by upto 5 nonadjacent oxygen atoms, or alkoxylate
groups of the formula --(CH.sub.2).sub.k--O---
(A.sup.1O).sub.m--(A.sup.2O).sub.n--Y where A.sup.1 and A.sup.2
are, independently of one another, 1,2-alkylene groups having 2 to
4 carbon atoms, Y is hydrogen, C.sub.1-C.sub.12-alkyl, phenyl or
C.sub.1-C.sub.4-alkoxycarbonyl, and k is 1, 2 or 3, and m and n are
each numbers from 0 to 50, and the total of m+n must be at least 4,
by reacting iminodiacetonitrile with aldehydes of the formula
R--CHO and HCN or alkali metal cyanides, the process being carried
out a) in the absence of an organic solvent and in the presence of
a Lewis or Bronsted acid, or b) in the presence or absence of an
organic solvent and in the presence of an emulsifier, or c) in the
presence or absence of an organic solvent and under a pressure in
the range from 1 to 40 bar.
Inventors: |
Rahm, Rainer; (Ludwigshafen,
DE) ; Greindl, Thomas; (Bad Duerkheim, DE) ;
Oftring, Alfred; (Bad Duerkheim, DE) ; Oetter,
Guenter; (Frankenthal, DE) ; Detering, Juergen;
(Limburgerhof, DE) ; Braun, Gerold; (Ludwigshafen,
DE) |
Correspondence
Address: |
OBLON SPIVAK MCCLELLAND MAIER & NEUSTADT PC
FOURTH FLOOR
1755 JEFFERSON DAVIS HIGHWAY
ARLINGTON
VA
22202
US
|
Assignee: |
BASF AKTIENGESELLSCHAFT
Ludwigshafen
DE
|
Family ID: |
7839779 |
Appl. No.: |
09/875995 |
Filed: |
June 8, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09875995 |
Jun 8, 2001 |
|
|
|
09463998 |
Mar 21, 2000 |
|
|
|
Current U.S.
Class: |
558/332 |
Current CPC
Class: |
C07C 229/16 20130101;
C07C 253/00 20130101; C07C 229/08 20130101; C07C 255/25 20130101;
C07C 253/00 20130101; C07C 255/25 20130101 |
Class at
Publication: |
558/332 |
International
Class: |
C07C 253/08 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 21, 1997 |
DE |
197 36 476.4 |
Aug 17, 1998 |
EP |
PCT/EP98/05220 |
Claims
We claim:
1. A process for preparing compounds of the formula IIb 9where R is
C.sub.6-C.sub.30-alkyl or C.sub.6-C.sub.30-alkenyl, which may
additionally have upto 5 hydroxyl groups, formyl groups,
C.sub.1-C.sub.4-alkoxy groups, phenoxy groups or
C.sub.1-C.sub.4-alkoxyca- rbonyl groups as substituents and may be
interrupted by upto 5 nonadjacent oxygen atoms, or alkoxylate
groups of the formula --(CH.sub.2).sub.k--O---
(A.sup.1O).sub.m--(A.sup.2O).sub.n--Y where A.sup.1 and A.sup.2
are, independently of one another, 1,2-alkylene groups having 2 to
4 carbon atoms, Y is hydrogen, C.sub.1-C.sub.12-alkyl, phenyl or
C.sub.1-C.sub.4-alkoxycarbonyl, and k is 1, 2 or 3, and m and n are
each numbers from 0 to 50, and the total of m+n must be at least 4,
by reacting iminodiacetonitrile with aldehydes of the formula
R--CHO and HCN or alkali metal cyanides, the process being carried
out a) in the absence or an organic solvent and in the presence of
a Lewis or Bronsted acid, or b) in the presence or absence of an
organic solvent and in the presence of an emulsifier, or c) in the
presence of absence of an organic solvent and under a pressure in
the range from 1 to 40 bar.
2. A process for preparing compounds of the formula IIa 10where R
has the meaning stated in claim 1, by reacting aldehydes of the
formula R--CHO with HCN or alkali metal cyanides and ammonia in the
presence of an organic base, wherein the reaction is carried out
under a pressure in the range from 1 to 40 bar.
3. A process for preparing compounds of the formula IIb as defined
in claim 1, by reacting compounds of the formula IIa as are defined
in claim 2 and can be prepared by the process claimed in claim 2,
with formaldehyde and HCN or alkali metal cyanides, wherein the
process is carried out in the presence or absence of a solvent
under a pressure in the range from 1 to 40 bar.
4. A process for preparing compounds of the formula IX 11where R
has the meaning stated in claim 1, and M is hydrogen, alkali metal,
alkaline earth metal, ammonium or substituted ammonium in the
appropriately stoichiometric amounts, by reacting compounds of the
formula IIb as are defined in claim 1 and can be prepared by a
process as claimed in claim 1 or 3, with alkali metal hydroxide
solutions and appropriate, with solutions which contain ions of M,
wherein the reaction with the alkali metal hydroxide solutions is
carried out under a pressure in the range from 1 to 40 bar.
5. A process for preparing compounds of the formula IV 12where R
has the meaning stated in claim 1 and M has the meaning stated in
claim 4, by reacting compounds of the formula IIa as are defined in
claim 2 and can be prepared by the process claimed in claim 2, with
alkali metal hydroxide solutions and, where appropriate, solutions
which contain ions of M, it being possible for aliphatic C.sub.3-9
ketones additionally to be present, wherein the reaction is carried
out under a pressure in the range from 1 to 40 bar.
6. A process for preparing compounds of the formula IX as defined
in claim 4, by reacting compounds of the formula IV as are defined
in claim 5 and can be prepared by the process claimed in claim 5,
with formaldehyde and HCN or alkali metal cyanide and subsequent
reaction with alkali metal hydroxide solutions and, where
appropriate, reaction with solutions which contain ions of M,
wherein the reactions are carried out under a pressure in the range
from 1 to 40 bar.
7. A process as claimed in claim 6, wherein the compounds of the
formula IV are obtained by acidic or alkaline hydrolysis of
hydantoins of the formula V 13where R has the meaning stated in
claim 1, it being possible to obtain the hydantoins by reacting,
under atmospheric or superatmospheric pressure, aldehydes of the
formula R--CHO with alkali metal cyanides and
ammoniumcarbonate.
8. A process for preparing compounds of the formula IX as defined
in claim 4 by reacting (B) iminodiacetic acid compounds of the
formula XIX--CH.sub.2--NH--H.sub.2--Y (XI)where X and Y are,
independently, CO.sub.2M, CO.sub.2R.sup.1 where
R.sup.1=C.sub.1-12-alkyl, CONH.sub.2 or CN, (a) with aldehydes of
the formula R--CHO and HCN or alkali metal cyanides, or (b) with
cyanohydrins of the formula R--CHO(OH)CN, in the presence of
absence of an organic solvent under a pressure in the range from 1
to 40 bar, or (C) glycine with aldehydes of the formula R--CHO and
HCN or alkali metal cyanides with monosubstitution and subsequently
with (a) formaldehyde and HCN or alkali metal cyanides or (b)
HO--CH.sub.2--CN in the presence or absence of an organic solvent,
it being possible to carry out the reaction under a pressure of
from 1 to 40 bar, or (D) glycine with (a) formaldehyde and HCN or
alkali metal cyanide, or (b) HO--CH.sub.2--CN, with
monosubstitution and subsequently with aldehydes of the formula
R--CHO and HCN or alkali metal cyanide in the presence or absence
of an organic solvent, it being possible to carry out the reaction
under a pressure of from 1 to 40 bar, where R in each case has the
meaning stated in claim 1, possibly followed by a hydrolysis of
nitrile or amide functionalities which are present, which can be
carried out under a pressure of from 1 to 40 bar.
9. A process as claimed in any of claims 2 to 8, which has one or
more of the following features: use of antifoams use of phase
transfer catalysts use of emulsifiers temperature in the range from
20 to 220.degree. C. pH in the range from 0 to 11.
10. A compound of the formula R--CHOR.sup.2R.sup.3 selected from
the compounds below 14where R' is C.sub.2-6-alkyl and R is
C.sub.6-20-alkenyl, excepting compounds of the formulae IV and V
with R=C.sub.17-20-alkenyl, of the formula T where R=n-9-decenyl
and of the formula VIII where R=C.sub.6-10-alkenyl, or R is the
radical R"O--CH.sub.2--CH.sub.2 where R" is C.sub.3-20-alkyl or
C.sub.3-20-alkenyl, excepting compounds of the formula IV with
R"=C.sub.5-20-alkyl and of the formula X where R"=C.sub.5-8-alkyl.
Description
[0001] The invention relates to a process for preparing long-chain
glycine-N,N-diacetic acid derivatives.
[0002] Glycine-N,N-diacetic acid derivatives can be employed as
biodegradable complexing agents for alkali metal and heavy metal
ions.
[0003] Various processes for preparing these compounds are
known.
[0004] WO 94/29421 describes processes for preparing
glycine-N,N-diacetic acid derivatives. These entail converting
long-chain aliphatic aldehydes with iminodiacetonitrile and HCN
alkylglycinonitrile-N,N-diacetonitrile, the resulting compound
being hydrolyzed. The compounds can likewise be obtained by
reacting the aldehydes with HCN and ammonia to give substituted
amino nitrites, which are hydrolyzed to substituted amino acids,
which is followed by reaction with formaldehyde and sodium cyanide.
The process is too complicated for some compounds because long
reaction times are necessary. Moreover the yields of the required
compounds are still in need of improvement. The proposed processes
are not always suitable for transfer to the industrial scale.
[0005] DE-A 195 18 986 describes a process for preparing
glycine-N,N-diacetic acid derivatives by reacting glycine
derivatives or their precursors with formaldehyde and hydrogen
cyanide or reacting iminodiacetonitrile or iminodiacetic acid with
appropriate aldehydes and hydrogen cyanide in aqueous acidic
medium. The starting material employed in this case is the
unpurified crude material derived from the industrial synthesis of
glycine derivatives or their precursors or of iminodiacetonitrile
or iminodiacetic acid, or mother liquors produced in syntheses of
these types. The process is carried out as indicated in WO
94/29421.
[0006] DE-A-195 18 187 relates to a process for preparing
glycine-N,N-diacetic acid derivatives by reacting glycine
derivatives or their precursors with formaldehyde and alkali metal
cyanide in aqueous alkali medium. The process is likewise based on
the process described in WO 94/29421, but firstly from 0.5 to 30%
of the amount of alkali metal cyanide required for the reaction is
added to the glycine derivatives or their precursors, and then the
remaining amount of alkali metal cyanide and the formaldehyde are
metered in simultaneously over a period of from 0.5 to 12 hours.
Even this variant of the process cannot eliminate all the
abovementioned disadvantages.
[0007] It is an object of the present invention to provide a
process for preparing glycine-N,N-diacetic acid derivatives by
reacting iminodiacetonitrile with aldehydes and HCN or alkali metal
cyanides, which avoids the abovementioned disadvantages and is
suitable for transfer to the industrial scale. The process ought to
give high yields in short reaction times; it is additionally
intended to provide alternative processes which avoid the
abovementioned disadvantages.
[0008] We have found that this object is achieved by processes with
several variants as described below by means of component steps.
The glycine-N,N-diacetic acid derivatives can be obtained, for
example, by reactions shown in the two reaction schemes detailed
below. 2
[0009] The processes according to the invention are additionally
explained by means of the reaction schemes depicted in the drawing,
where
[0010] FIG. 1 shows reaction schemes A and B based on dodecanal as
example and
[0011] FIG. 2 shows reactions schemes A1 and A2 for aldehydes of
the formula R--CHO, where R has the meaning indicated hereinafter.
The object is achieved in particular by a process for preparing
compounds of the formula IIb 3
[0012] where R is C.sub.6-C.sub.30-alkyl or
C.sub.6-C.sub.30-alkenyl, which may additionally have upto 5
hydroxyl groups, formyl groups, C.sub.1-C.sub.4-alkoxy groups,
phenoxy groups or C.sub.1-C.sub.4-alkoxyca- rbonyl groups as
substituents and may be interrupted by upto 5 nonadjacent oxygen
atoms, or alkoxylate groups of the formula --(CH.sub.2).sub.k13
O--(A.sup.1O).sub.m--(A.sup.2O).sub.n--Y where A.sup.1 and A.sup.2
are, independently of one another, 1,2-alkylene groups having 2 to
4 carbon atoms, Y is hydrogen, C.sub.1-C.sub.12-alkyl, phenyl or
C.sub.1-C.sub.4-alkoxycarbonyl, and k is 1, 2 or 3, and m and n are
each numbers from 0 to 50, and the total of m+n must be at least
4,
[0013] by reacting iminodiacetonitrile with aldehydes of the
formula R--CHO and HCN or alkali metal cyanides, the process being
carried out
[0014] a) in the absence of an organic solvent and in the presence
of a Lewis or Bronsted acid, or
[0015] b) in the presence or absence of an organic solvent and in
the presence of an emulsifier, or
[0016] c) in the presence or absence of an organic solvent and
under a pressure in the range from 1 to 40 bar.
[0017] It has been found according to the invention that reactions
with aldehydes and HCN or alkali cyanides, as well as the
hydrolysis of nitrites or amides to acids, can be speeded up and,
moreover, the yield is increased under an elevated pressure in the
range from 1 to 40 bar, preferably from 1.5 to 30 bar, in
particular from 2 to 15 bar. These preferred pressure ranges also
relate to the other reactions mentioned. Reaction of
iminodiacetonitrile with aldehydes and HCN can moreover be speeded
up by reacting in the absence of an organic solvent and, in
particular, in the absence of further water in the reaction system,
ie. by reacting without diluent and in the presence of a Lewis or
Bronsted acid.
[0018] The reaction can additionally be carried out in the presence
of an emulsifier, which is preferably employed in a concentration
of from 1 to 50 g/l, particularly preferably 2 to 30 g/l of
reaction mixture. Emulsifiers which can be employed are all
compounds suitable for this purpose. Examples are anionic,
cationic, amphoteric and nonionic emulsifiers. The lipophilic end
groups of the emulsifiers are, as a rule, straight-chain or
branched alkyl radicals which may contain unsaturated bonds, aryl
radicals or alkylaryl radicals. Examples of suitable hydrophilic
end groups for anionic emulsifiers are carboxylate, sulfonate,
sulfate, phosphate, polyphosphate, lactate, citrate and tartrate.
Suitable examples of cationic emulsifiers are amine salts and
quaternary ammonium compounds. Suitable amphoteric emulsifiers are
zwitterionic compounds of the amino acid type and, for example,
betaine. Suitable for nonionic emulsifiers are residues of
alcohols, polyethers, glcyerol, sorbitol, pentaerythritol, sucrose,
acidic acid or lactic acid. The emulsifiers may additionally have
hydrophilic groups in between such as hydroxyl, ester, sulfamide,
amide, polyamide, polyamine, amine, ether, polyether, glycerol,
sorbitol, pentaerythritol or sucrose groups.
[0019] Examples of suitable emulsifiers are ethoxylation products
and fatty acid condensation products, fatty alcohol ethoxylates
and, where appropriate, polyglycols and products of the reaction of
phenols and oils with ethylene oxide.
[0020] The emulsifiers particularly employed are compounds such as
alkali metal alkyl sulfates, in particular sodium dodecyl sulfate
or mixtures of hydrophobic alkyl sulfates. It is also possible to
employ nonionic surfactants such as fatty alcohol ethoxylates,
which are, in particular, low-foaming.
[0021] The process step indicated above relates to process B for
converting the initial aldehyde into the compound of the formula
IIb.
[0022] The invention also relates to a process for preparing
compounds of the formula IIa 4
[0023] where R has the abovementioned meaning, by reacting
aldehydes of the formula R--CHO with HCN or alkali metal cyanides
and ammonia in the presence of an organic base, the reaction being
carried out under a pressure in the range from 1 to 40 bar. In FIG.
1, this reaction corresponds to the conversion of the initial
aldehyde into the compound of the formula IIa.
[0024] The invention likewise relates to a process for preparing
compounds of the formula IIb as defined above, by reacting
compounds of the formula IIa as are defined above and can be
prepared by the above process, with formaldehyde and HCN or alkali
metal cyanides, the process being carried out in the presence or
absence of a solvent under a pressure in the range from 1 to 40
bar. This reaction corresponds to the step for converting the
compound of the formula IIa into the compound of the formula IIb in
FIG. 1.
[0025] The invention furthermore relates to a process for preparing
compounds of the formula IX 5
[0026] where R has the abovementioned meaning, and M is hydrogen,
alkali metal, alkaline earth metal, ammonium or substituted
ammonium in the appropriately stoichiometric amounts, by reacting
compounds of the formula IIb as are defined above and can be
prepared by an above process, with alkali metal hydroxide solutions
with or without solutions which contain ions of M, the reaction
with the alkali metal hydroxide solutions being carried out under a
pressure in the range from 1 to 40 bar. This reaction corresponds
to the process step from the compound of the formula IIb to the
compound of the formula IXa in FIG. 1.
[0027] The invention further relates to a process for preparing
compounds of the formula IV 6
[0028] where R and M have the abovementioned meanings, by reacting
compounds of the formula IIa as are defined above and can be
prepared by the above process, with sodium hydroxide solution,
alkali metal hydroxide solutions and, where appropriate, solutions
which contain ions of M, in the additional presence of aliphatic
C.sub.3-9 ketones, the reaction being carried out under a pressure
in the range from 1 to 40 bar. This reaction step corresponds to
the step for converting the compound of the formula IIa to the
compound of the formula IV in FIGS. 1 and 2.
[0029] The invention additionally relates to a process for
preparing compounds of the formula IX as defined above, by reacting
compounds of the formula IV as are defined above and can be
prepared by the above process, with formaldehyde and HCN or alkali
metal cyanide and subsequent reaction with alkali metal hydroxide
solutions and reaction with solutions which contain ions of M, the
reactions being carried out under a pressure in the range from 1 to
40 bar. This reaction step is a step in FIGS. 1 and 2 from the
compound of the formula IV to the compound of the formula IXa.
Compounds of the formula IV can also be obtained by acidic or
alkaline hydrolysis of hydantoins of the formula V 7
[0030] where R has the abovementioned meaning, it being possible to
obtain the hydantoins by reacting, under atmospheric or
superatmospheric pressure, aldehydes of the formula R--CHO with
alkali metal cyanides and ammonium carbonate.
[0031] Besides the two process variants A and B (specific), the
invention also relates to the following process variants B
(general) C and D. In this connection, the invention relates to a
process for preparing compounds of the formula IX as defined above
by reacting
[0032] (B) iminodiacetic acid compounds of the formula XI
X--CH.sub.2--NH--CH.sub.2--Y (XI)
[0033] where X and Y are, independently, CO.sub.2M,
CO.sub.2R.sup.1
[0034] where R.sup.1=C.sub.1-12-alkyl, CONH.sub.2 or CN,
[0035] (a) with aldehydes of the formula R--CHO and HCN or alkali
metal cyanides, or
[0036] (b) with cyanohydrins of the formula R--CHO(OH)CN, in the
presence of absence of an organic solvent under a pressure in the
range from 1 to 40 bar, or
[0037] (C) glycine with aldehydes of the formula R--CHO and HCN or
alkali metal cyanides with monosubstitution and subsequently
with
[0038] (a) formaldehyde and HCN or alkali metal cyanides or
[0039] (b) HO--CH.sub.2--CN in the presence or absence of an
organic solvent, it being possible to carry out the reaction under
a pressure of from 1 to 40 bar, or
[0040] (D) glycine with
[0041] (a) formaldehyde and HCN or alkali metal cyanide, or
[0042] (b) HO--CH.sub.2--CN,
[0043] with monosubstitution and subsequently with aldehydes of the
formula R--CHO and HCN or alkali metal cyanide in the presence or
absence of an organic solvent, it being possible to carry out the
reaction under a pressure of from 1 to 40 bar,
[0044] where R in each case has the abovementioned meaning,
[0045] possibly followed by a hydrolysis of nitrile or amide
functionalities which are present, which can be carried out under a
pressure of from 1 to 40 bar.
[0046] Process variant C complies with the following scheme:
R--CHO+glycine+HCN.fwdarw.NC--CHR--NH--CH.sub.2--COOH
H.sub.2CO+HCN.fwdarw..fwdarw.NC--CHRN(CH.sub.2CN)--COOH.fwdarw.compound
of the formula IX.
[0047] Reaction sequence D complies with the following scheme:
[0048]
Glycine+H.sub.2CO+HCN.fwdarw.NC--CH.sub.2--NH--CH.sub.2--COOH+R--CH-
O+HCN.fwdarw.NC--CHR--N(CH.sub.2--CN)--CH.sub.2--COOH.fwdarw.compound
of the formula IX.
[0049] The processes detailed above can additionally be improved by
using one or more of the following process variants: use of
antifoams use of phase transfer catalysts, use of emulsifiers,
temperature in the range from 20 to 220.degree. C., preferably 30
to 180.degree. C., in particular 50 to 140.degree. C., pH in the
range from 0 to 11. If the reactions are carried out under
superatmospheric pressure, the pressure is preferably from 1.5 to
30 bar, in particular 2 to 15 bar.
[0050] The invention furthermore relates to compounds which arise
during the reaction schemes detailed above. These compounds have
the formula R--CHR.sup.2R.sup.3 selected from the compounds below
8
[0051] where R' is C.sub.2-6-alkyl and R is C.sub.6-20-alkenyl,
excepting compounds of the formulae IV and V with
R=C.sub.17-20-alkenyl, of the formula I where R=n-9-decenyl and of
the formula VIII where R=C.sub.6-10-alkenyl,
[0052] or R is the radical R"O--CH.sub.2--CH.sub.2 where R" is
C.sub.3-20-alkyl or C.sub.3-20-alkenyl, excepting compounds of the
formula IV with R"=C.sub.5-20-alkyl and of the formula X where
R"=C.sub.5-8-alkyl.
[0053] The compounds are particularly those where R is
C.sub.12-20-alkenyl and R" is C.sub.6-15-alkyl or
C.sub.3-12-alkenyl.
[0054] Before detailed description of the processes according to
the invention, the compounds employed according to the invention
are described in detail.
[0055] Suitable alkali metal, ammonium and substituted ammonium
salts are, in particular, the sodium, potassium and ammonium salts,
and in the case of the compounds of the formula IX, in particular
the trisodium, tripotassium and triammonium salt, and organic
triamine salts with a tertiary nitrogen atom.
[0056] Particularly suitable bases underlying the organic amine
salts are tertiary amines such as trialkylamines having 1 to 4
carbon atoms in the alkyl, such as trimethyl- and triethylamine,
and trialkanolamines having 2 or 3 carbon atoms in the alkanol
residue, preferably triethanolamine, tri-n-propanolamine or
triisopropanolamine.
[0057] The alkaline earth metal salts which are particularly
employed are the calcium and magnesium salts.
[0058] Particularly suitable straight-chain or, branched alk(en)yl
radicals for the R radical are C.sub.6-C.sub.20-alkyl and -alkenyl,
and of these in particular straight-chain radicals derived from
saturated or unsaturated fatty acids. Examples of individual R
radicals are: n-hexyl, n-heptyl, 3-heptyl (derived from
2-ethylhexanoic acid), n-octyl, isooctyl (derived from isononanoic
acid), n-nonyl, n-decyl, n-undecyl, n-dodecyl, isododecyl (derived
from isotridecanoic acid), n-tridecyl, n-tetradecyl, n-pentadecyl,
n-hexadecyl, n-heptadecyl, n-octadecyl, n-nonadecyl, n-eicosyl and
n-heptadecenyl (derived from oleic acid). Mixtures may also occur
for R, in particular those derived from naturally occurring fatty
acids and from synthetic industrial acids, for example those
produced by the oxo synthesis.
[0059] Particularly used as Cl-C.sub.12-alkylene bridges A are
polymethylene groups of the formula --(CH2).sub.k-- where k is a
number from 2 to 12, in particular from 2 to 8, ie. 1,2-ethylene,
1,3-propylene, 1,4-butylene, pentamethylene, hexamethylene,
heptamethylene, octamethylene, nonamethylene, decamethylene,
undecamethylene and dodecamethylene. Hexamethylene, octamethylene,
1,2-ethylene and 1,4-butylene are particularly preferred in this
connection. However, it is also possible for branched
C.sub.1-C.sub.12-alkylene groups to occur, for example
--CH.sub.2CH(CH.sub.3)CH.sub.2--, --CH.sub.2C(CH.sub.3).sub.2-
--CH.sub.2--, --CH.sub.2CH(C.sub.2H.sub.5)-- or
--CH.sub.2CH(CH.sub.3)--.
[0060] The C.sub.6-C.sub.30-alkyl and C.sub.6-C.sub.30-alkenyl
groups may have upto 5, in particular upto 3, additional
substituents of the type mentioned, and be interrupted by upto 5,
in particular upto 3, nonadjacent oxygen atoms. Examples of such
substituted alk(en)yl groups are --CH.sub.2OH,
--CH.sub.2CH.sub.2OH, --CH.sub.2CH.sub.2--O--CH.sub.3,
--CH.sub.2CH.sub.2--O--CH.sub.2CH.sub.2--O--CH.sub.3,
--CH.sub.2--O--CH.sub.2CH.sub.3,
--CH.sub.2--O--CH.sub.2CH.sub.2--OH, --CH.sub.2--CHO,
--CH.sub.2--OPh, --CH.sub.2--COOCH.sub.3 or
--CH.sub.2CH.sub.2--COOCH.sub.3.
[0061] Particularly suitable alkoxylate groups are those where m
and n are each numbers from 0 to 30, especially from 0 to 15.
A.sup.1 and A.sup.2 are groups derived from butylene oxide and,
especially, from propylene oxide and from ethylene oxide. Pure
ethoxylates and propoxylates are of particular interest, but
ethylene oxide/propylene oxide block structures may also occur.
[0062] In the first place, process variant A which comprises two
reaction routes A1 and A2 as depicted in FIG. 2 will be
explained.
[0063] The long-chain .alpha.-amino nitrites of the formula IIa can
be prepared from the corresponding cyanohydrins and liquid ammonia
or highly concentrated aqueous ammonia solutions (concentrations
from 30 to 80% by weight) or from the corresponding long-chain
aldehydes, hydrogen cyanide and liquid ammonia or highly
concentrated aqueous ammonia solutions. Starting materials which
can be used besides pure compounds are the starting materials
described in DE-A-195 18 986 from the industrial synthesis of
monoaldehydes. Particularly used are mixtures of aldehydes or
mixtures of aldehydes and the corresponding alcohols. In process
variant A, the starting materials are preferably those from the
industrial synthesis of .alpha.-amino nitrites, .alpha.-amino acids
or their precursors, by which is meant the underlying cyanohydrins
or the corresponding aldehydes or the hydantoins substituted in
position 5. Unpurified crude material or the mother liquors
produced are preferably employed.
Preferred Embodiments of Variant A
Variant A
[0064] The .alpha.-amino nitrile of the formula IIa or the amino
acid of the formula IV is reacted with 1.8 to 3.0 eq, in particular
2.0 to 2.5 eq, of hydrogen cyanide (HCN) and, simultaneously or
sequentially, with 1.8 to 3.0 eq, in particular 2.0 to 2.5 eq, of
formaldehyde in water or a mixture of water and a water-miscible
organic solvent such as alcohols, ethers, etc., in particular
alcohols such as methanol, ethanol, n-propanol, i-propanol,
tertbutanol, with a water content of from 1 to 99%, in particular
20 to 80%, at a pH of from 0 to 11, within from 0.5 to 12 hours, in
particular 1 to 5 hours. Stirring is then normally continued for
from 0.5 to 20 hours, in particular 3 to 10 hours, under the
reaction conditions. The cyanomethylation can in both embodiments
also be carried out stepwise and with isolation of the
mono(cyanomethyl) stage. It is also possible to employ
glycolonitrile in place of formaldehyde and hydrogen cyanide.
Hydrolysis is subsequently carried out, where appropriate after
isolation of the intermediate product (XII) by filtration or
decantation, normally in embodiment A2 with 2.4 to 6, in particular
3 to 5, and in embodiment A1 with 1.6 to 4, in particular 2 to 3
mole equivalents of bases able to release hydroxide ions in aqueous
medium, such as alkali metal hydroxides, ammonium hydroxides,
barium hydroxide, calcium hydroxide or alkali metal alcoholates,
preferably aqueous sodium or potassium hydroxide solution or
alcoholic sodium or potassium hydroxide solution, for example
ethanolic sodium or potassium hydroxide solution, with an alcohol
content of from 5 to 50%, in particular 10 to 40%, under a pressure
of from 1 to 40 bar, in particular 2 to 15 bar, and from 20 to
220.degree. C., in particular from 30 to 160.degree. C. A
particular embodiment of the hydrolysis comprises the ammonia which
is produced being continuously decompressed to the set pressure
through a relief valve when a preset pressure of from 1.5 and 10
bar, in particular 2 to 6 bar is reached.
[0065] The hydrophobic .alpha.-amino nitriles are obtained
according to the invention either from the corresponding
cyanohydrins and from 1 to 10 eq, in particular 3 to 8 eq, of
liquid ammonia or 1 to 20 eq, in particular 3 to 15 eq, of a highly
concentrated aqueous ammonia solution, preferably 30 to 80%
strength ammonia, or directly from the underlying monoaldehydes,
hydrogen cyanide and 1 to 10 eq, in particular 3 to 8 eq, of liquid
ammonia or 1 to 20 eq of preferably 30 to 80% strength ammonia
under a pressure of 1 to 40 bar, in particular 2 to 15 bar.
Stirring is then normally continued for from 0.1 to 12 h, in
particular 0.5 to 6 h, at from 0 to 35.degree. C. under the
reaction conditions. The initial temperature is preferably
0.degree. C., which is gradually raised to 35.degree. C.
[0066] When amino nitrites are synthesized by known methods in the
case of long-chain products the resulting reaction mixtures in some
cases have a very high content of the unwanted imino dinitriles
which result from the reaction between 1 molecule each of
.alpha.-aminonitrile and unreacted cyanohydrin and which may cause
problems in subsequent reactions. The yields of required product
are then also frequently unsatisfactory and uneconomic.
[0067] Said technical improvements in the processes result in the
amounts of these by-products being reduced to <5 mol % and, in
the optimal case, production thereof being completely suppressed. A
preferred embodiment proves to be reaction of the cyanohydrin
either pure or in a suitable organic solvent, in particular
alcohols, in liquid ammonia.
[0068] Hydrolysis is subsequently carried out, where appropriate
after phase separation, filtration or decantation, normally with
0.8 to 2, in particular 1 to 1.5, mole equivalents of aqueous
sodium or potassium hydroxide solution or alcoholic sodium or
potassium hydroxide solution, for example ethanolic sodium or
potassium hydroxide solution with an alcohol content of from 5 to
50%, in particular 10 to 40%, based on amino nitrile to be reacted,
where appropriate under a pressure of from 1 to 40 bar, in
particular 2 to 15 bar, and from 20 to 220.degree. C., in
particular 30 to 160.degree. C.
[0069] The ammonia which is produced is continuously decompressed
to the preset pressure through a relief valve when a preset
pressure of from 1.5 to 10 bar, in particular 2 to 6 bar, is
reached.
[0070] Alternatively, the amino nitrites can be hydrolyzed to the
amino acids by saturated solution of hydrogen chloride in alcohols,
in particular ethanol etc. It has proven beneficial to carry out
the hydrolysis in the presence of substoichiometric amounts of
alkali metal or alkaline earth metal hydroxides, in particular
aqueous sodium or potassium hydroxide solution, with the addition
of ketones, in particular acetone, starting the hydrolysis at
temperatures <30.degree. C. It is possible by this procedure to
suppress cleavage of the amino nitrites back to the aldehyde and to
optimize further the yields of amino acid. The .alpha.-amino amides
initially obtained under mild reaction conditions can be either
isolated and hydrolyzed further under normal hydrolysis conditions
and under pressure or hydrolyzed further directly in the reaction
solution after addition of appropriate amounts of aqueous alkali at
elevated temperature and under superatmospheric pressure. This
mechanical improvement in the process for hydrolyzing hydrophobic
amino nitrites is expediently carried out in such a way that the
first reaction step takes place with the addition of, preferably,
0.1 to 0.9, in particular 0.15 to 0.7, mole equivalents of alkali
and 0.2 to 2, in particular 0.3 to 1, mole equivalents of the
relevant ketone and from 5 to 40.degree. C., in particular 10 to
30.degree. C. For the further hydrolysis to the amino acids, the
alkali content is increased to stoichiometric amounts, and
hydrolysis is continued under superatmospheric pressure.
[0071] The amino acids employed for preparing long-chain
glycine-N,N-diacetic acids can, however, also be obtained by acidic
or alkaline hydrolysis under a pressure of from 1 to 40 bar of the
5-substituted hydantoins obtainable from the corresponding
aldehydes, alkali metal cyanide and ammonium carbonate.
[0072] The cyanohydrins are normally prepared by known methods from
the corresponding aldehyde and hydrocyanic acid with addition of
bases such as triethylamine, alkali metal cyanides etc. without
diluent or in the presence of a suitable organic solvent, in
particular of alcohols.
[0073] The long-chain monoaldehydes employed in variants A and B
are preferably derived from processes which can be carried out
industrially to prepare them from easily available and low-cost
basic chemicals, in particular hydroformylation reactions of
corresponding .alpha.-olefins and metal-catalyzed reductions of the
underlying carboxylic acids and esters. It has proven particularly
advantageous to employ mixtures of aldehydes and alcohols as
typically produced in a number of processes of this type. This
makes it possible to dispense with addition of a water-miscible
organic solvent such as methanol, ethanol, isopropanol, dioxane,
etc. in the individual process steps. The alcohol which is present
has not only solubilizing but also antifoam properties which may
make a very advantageous contribution to reducing the unwanted
foaming due to the evolution of ammonia at the hydrolysis stage. It
is unnecessary to remove these alcohols from the product or the
product properties. Mixtures of isomeric and homologous aldehydes
as are produced in many industrial syntheses can also be reacted
successfully.
[0074] The addition, according to the invention of a suitable
emulsifier which is able to disperse the aldehydes, cyanohydrins,
amino nitrites, amino amides or amino acids sufficiently well in
the purely aqueous medium, in a concentration of 1 to 50 g/l of
reaction mixture, in particular 2 to 30 g/l, results in a marked
reduction in the reaction times by comparison with reaction without
emulsifier. This variant of the process results in reaction times
like those which can be obtained in Strecker reactions on amino
nitrites or amino acids under superatmospheric pressure at elevated
temperatures in an autoclave. It is particularly beneficial to
carry out the reactions in the presence of an emulsifier under
superatmospheric pressure. Examples of emulsifiers which can be
employed successfully are sodium dodecyl sulfate, sodium
dodecylbenzenesulfonate (LAS) and mixtures of hydrophobic alkyl
sulfates. It is also possible to employ nonionic surfactants such
as fatty alcohol ethoxylates, some of which are low-foam
surfactants. The reaction times are also reduced on use of phase
transfer catalysts which are able to bring about a rapid phase
exchange between the hydrophobic components of aldehydes,
cyanohydrins, amino nitrites, amino amides or amino acids,
formaldehyde and hydrogen cyanide, and sodium cyanide in the
aqueous or aqueous alcoholic system. Examples of phase transfer
catalysts used are quaternary ammonium, phosphonium and other onium
compounds, crown ethers and cryptands. Examples are
tetraalkylammonium salts, trialkylbenzylammonium salts,
tetraalkylphosphonium salts and other corresponding quaternary
salts.
[0075] In some variants of the processes described hereinbeforehand
and hereinafter, the occurrence of foaming, in particular at the
hydrolysis stage due to the ammonia which is produced, may cause
problems. Addition of small or very small amounts of an antifoam,
preferably a silicone antifoam, results in collapse of the foam or
a reduction to a minimum which can be satisfactorily controlled
industrially. It is also possible to employ other antifoam
substances such as fatty alcohol ethoxylates, phosphoric esters
etc. Addition of such substances is unnecessary if the reactions
take place in aqueous alcoholic media, or mixtures of long-chain
aldehydes and corresponding alcohols are employed. Addition of
surfactants such as alcohol alkoxylates is particularly
advantageous because they remain in the product after the reaction
has taken place and can be employed in the mixture.
[0076] If the compounds IX result as salts, the free acids of the
compounds IX can be obtained by acidification by conventional
methods.
Variant B
[0077] The reaction according to the invention of
iminodiacetonitrile, iminodiacetic acid or their derivatives, in
particular iminodiacetic esters or iminodiacetamides, with the
appropriate long-chain aldehydes and hydrogen cyanide in embodiment
B takes place either by reacting crude iminodiacetonitrile or
iminodiacetonitrile-containing mother liquors with the aldehyde and
hydrocyanic acid to give the corresponding
glycinonitrile-N,N-diacetonitrile, followed by alkaline hydrolysis
to the compounds IX under a pressure of from 1 to 40 bar, in
particular 2 to 15 bar, at from 20 to 220.degree. C., in particular
50 to 140.degree. C., or by alkaline hydrolysis of the
iminodiacetonitrile to the iminodiacetic acid and, where
appropriate, its conversion into derivatives by known methods, in
particular iminodiacetic esters or iminoacetamides, followed by
reaction with the aldehyde and hydrocyanic acid under a pressure of
from 1 to 40 bar, in particular 2 to 15 bar and from 20 to
220.degree. C., in particular 50 to 140.degree. C. Higher pressures
are also possible, for example, by injecting protective gas such as
nitrogen.
[0078] The iminodiacetonitrile is often reacted as 5 to 30% by
weight mother liquor with 0.8 to 5.0 eq, in particular 1 to 3 eq,
of hydrogen cyanide and, simultaneously or sequentially, with 0.8
to 3.0 eq, in particular 1.0 to 1.5 eq, of the long-chain aldehyde
in water or a mixture of water and a water-miscible organic
solvent, in particular alcohols, with a water content of from 1 to
99%, in particular 20 to 80%, at a pH of, preferably, 0 to 5, which
is normally adjusted by adding mineral acids, within from 1 to 15
hours, in particular 2 to 6 hours, under superatmospheric pressure
in an autoclave. Stirring is then normally continued for 0.5 to 20
hours, in particular 3 to 10 hours, under the reaction conditions.
Hydrolysis is ultimately carried out, if appropriate after
isolation of the intermediate by filtration or decantation,
normally with 2 to 5, in particular 3 to 4, mol equivalents of
bases able to release hydroxide ions in an aqueous medium, such as
alkali metal hydroxides, ammonium hydroxides, barium hydroxide,
calcium hydroxide or alkali metal alcoholates, preferably aqueous
sodium or potassium hydroxide solution or alcoholic sodium or
potassium hydroxide solution, in particular ethanolic sodium or
potassium hydroxide solution, with an alcohol content of from 5 to
50%, in particular 10 to 40%, based on iminodiacetonitrile
employed, under superatmospheric pressure. A particular embodiment
of the hydrolysis consists in continuously decompressing the
ammonia which is produced to the preset pressure through a relief
valve when a preset pressure of from 1.5 to 10 bar, in particular 2
to 6 bar, is reached.
Variants C, D
[0079] The reaction according to the invention of unsubstituted
glycine, its precursors or its secondary products
cyanomethylglycine and carboxymethylglycine, which are obtainable
by monosubstitution of glycine with formaldehyde and hydrogen
cyanide, with the appropriate long-chain aldehydes and hydrogen
cyanide in embodiments C and D is normally carried out under a
pressure of from 1 to 40 bar, in particular 2 to 15 bar, from 20 to
220.degree. C., in particular 50 to 140.degree. C. Higher pressures
are also possible, for example by injecting protective gas such as
nitrogen. The pH of the aqueous or organic aqueous, in particular
alcoholic aqueous, reaction medium with a water content of from 1
to 99%, in particular 20 to 80% is from 0 to 11, preferably 1 to
10. Precursors of glycine mean, for example glycinonitrile.
[0080] The formaldehyde and the hydrogen cyanide are metered
simultaneously into glycine or its precursors at the stated
reaction temperature and the stated pH over a period of from 0.1 to
12 hours, in particular 0.15 to 6 hours, especially 0.25 to 3
hours. Reaction is then normally allowed to continue for 1 to 20
hours, preferably 2 to 10 hours, under the reaction conditions.
[0081] In embodiment C it is expedient to employ per mol equivalent
of glycine or its precursors used as starting material for the
first substitution step from 1.0 to 1.05 eq of the long-chain
aldehyde, preferably as technical product, and 1.0 to 1.6, in
particular 1.0 to 1.4, eq of hydrogen cyanide, and for the second
substitution step from 1.0 to 1.6 eq, in particular 1.0 to 1.4 eq,
of formaldehyde, preferably in the form of its aqueous solution
which is about 30% by weight, and from 1.0 to 1.6, in particular
1.0 to 1.4, eq of hydrogen cyanide. Normally used as starting
material are aqueous solutions of glycine or its precursors with a
glycine or precursor content of from 10 to 50% by weight, in
particular 25 to 45% by weight.
[0082] In embodiment D it is expedient to employ per mol equivalent
of the glycine or its precursors used as starting material for the
first substitution step from 1.0 to 1.05 eq of formaldehyde,
preferably in the form of its aqueous solution which is about 30%
by weight, and from 1.0 to 1.6, in particular 1.0 to 1.4, eq of
hydrogen cyanide, and for the second substitution step from 1.0 to
1.6 eq, in particular 1.0 to 1.4 eq, of the long-chain aldehyde,
preferably as technical product, from 1.0 to 1.6, in particular 1.0
to 1.4, eq of hydrogen cyanide.
[0083] The hydrolysis of nitrile functionalities which are present
after the reaction to give carboxylate groups is normally carried
out with from 0.8 to 2.0, in particular 1.0 to 1.5, mol equivalents
per nitrile functionality of aqueous sodium or potassium hydroxide
solution or alcoholic sodium or potassium hydroxide solution, such
as ethanolic sodium or potassium hydroxide solution with an alcohol
content of from 5 to 50%, in particular under pressures from 2 to
15 bar and at from 20 to 220.degree. C., in particular from 50 to
140.degree. C. Higher pressures are also possible, for example by
injecting protective gas such as nitrogen. It has proven to be
particularly beneficial for the ammonia which is produced to be
continuously decompressed to the preset pressure through a relief
valve when a preset pressure of from 1 to 10 bar, in particular 2
to 6 bar, is reached.
[0084] In place of the long-chain aldehydes, formaldehyde and
hydrogen cyanide, it is also possible for their synthetic
equivalents, the corresponding hydrophobic cyanohydrins and
glycolonitrile to be reacted in a similar way to the individual
components in embodiments B, C or D.
[0085] By-products found in the particular hydrolysis solutions are
occasionally small amounts of the corresponding .alpha.-hydroxy
carboxylic acids and fatty acids produced on hydrolysis with
unreacted cyanohydrin or the cyanohydrin formed as intermediate
from aldehyde and hydrogen cyanide. Since these compounds have a
beneficial effect on the properties of the product, they need not
be removed from the reaction mixtures, which is why costly and
elaborate purification steps are unnecessary.
[0086] Addition according to the invention of a suitable emulsifier
which is able to disperse the particular long-chain aldehyde
sufficiently well in the purely aqueous medium, in a concentration
of from 1 to 50 g/l of reaction mixture, in particular 2 to 30 g/l,
results in a marked reduction in the reaction times in embodiments
B to D compared with reaction without emulsifier. This technical
improvement in the process results in reaction times which are in
the region of the Strecker reactions under superatmospheric
pressure. Accordingly it is particularly beneficial to carry out
the reactions in the presence of an emulsifier under
superatmospheric pressure. Examples of emulsifiers which can be
employed successfully are sodium dodecyl sulfate and mixtures of
hydrophobic alkyl sulfates. The use of nonionic surfactants such as
fatty alcohol ethoxylates and nonionic low-foam surfactants such as
specific fatty alcohol alkoxylates or mixtures of nonionic
surfactants and aldehydes equally has beneficial effects on the
reaction times and yields as for variant A. These emulsifiers or
surfactants may also remain in the product if required, and
advantageously do not need to be removed because they may
supplement or have a beneficial effect on the product
properties.
[0087] The reaction times are also reduced on use of phase transfer
catalysts which are able to bring about a rapid phase exchange
between the long-chain aldehyde, iminodiacetonitrile and hydrogen
cyanide in the aqueous or aqueous alcoholic system or between the
long-chain aldehyde, glycine, its precursors or its secondary
products cyanomethylglycine and carboxymethylglycine and hydrogen
cyanide (variants C and D). Phase transfer catalysts which are used
are described above for variant A.
[0088] The preparation process without diluent is particularly
preferred, that is to say in the melt without use of additional
solvents. In this case, the abovementioned emulsifiers are
preferably employed. It is likewise particularly advantageous for
the reaction to take place in the presence of alcohols, which may
also have an emulsifying effect. The hydrolysis preferably takes
place under elevated pressure, with the reaction mixture being
decompressed to the required pressure if a maximum permissible
pressure is exceeded. The preferred processes are explained in
detail by means of examples below. The preferred alcohols are also
indicated therein.
[0089] The reaction can also be carried out in accordance with the
metering instructions given in DE-A-195 18 987. Further procedures
can be found in WO 94/29421.
[0090] The invention is explained in detail by means of examples
below.
EXAMPLES
Example 1
D,L-2-Aminotridecanonitrile
[0091] 27 g (1 mol) of hydrocyanic acid are metered over the course
of 30 minutes into a mixture of 190 g (1 mol) of 97% pure
lauraldehyde and 12.2 g (0.12 mol) of triethylamine at 15.degree.
C. in a steel autoclave under atmospheric pressure. The mixture is
then heated at 40.degree. C. for 2 hours until aldehyde is no
longer detectable in the IR spectrum. The reactor is closed, 73 g
(4.3 mol) of liquid ammonia are condensed in at about 25.degree. C.
This sets up a pressure of 12 bar. The mixture is then stirred
under the same conditions for 1 h before being decompressed to
atmospheric pressure, the ammonia escaping. For stability reasons,
the product is not worked up further but is reacted immediately.
The content is determined by GC, the yield of amino nitrile
determined thereby being 204 g (0.97 mol; 97% of theory).
Example 2
D,L-n-undecylglycine-N,N-diacetic acid
[0092] 7.5 g (0.05 mol) of a 33% strength sodium cyanide solution
are added to a solution of 59.1 g (0.25 mol) of 89% pure
2-aminotridecanonitrile from Example 1 in 150 ml of ethanol in a
steel autoclave. The reactor is closed and then heated to
100.degree. C. before simultaneously metering in 68.2 g (0.46 mol)
of a 33% strength sodium cyanide solution and 51 g (0.51 mol) of a
30% strength formaldehyde solution over the course of 1 h. The
mixture is stirred at the same temperature under a pressure of
about 4 bar for 3 h until no further change in the cyanide content
can be found by titration. After addition of 20 g (0.25 mol) of 50%
strength sodium hydroxide solution, the reaction solution is
hydrolyzed further at 100.degree. C. under about 4 bar for 6 h.
After cooling and decompression to atmospheric pressure, the
volatile constituents are distilled off and the residue is taken up
in water. The pH is then adjusted to 2 with concentrated
hydrochloric acid, and the precipitate which forms is isolated by
filtration. 82.6 g (0.23 mol) of 97% pure
D,L-n-undecylglycinediacetic acid with a calcium binding capacity
of 2.81 mmol/g are obtained, corresponding to a yield of 93% of
theory.
Example 3
D,L-2-aminotridecanoic acid
[0093] 6.4 g (0.11 mol) of acetone and 4 g (0.05 mol) of 50%
strength sodium hydroxide solution are added successively to 105.2
g (0.25 mol) of a 50% strength solution of
D,L-2-aminotridecanonitrile in ethanol at 10.degree. C. in a steel
autoclave. After warming to room temperature, the mixture is
stirred for 30 minutes before being diluted with 50 ml of water,
and a further 16 g (0.2 mol) of 50% strength sodium hydroxide
solution are metered in. The reactor is closed and heated at
160.degree. C. for 30 min, a pressure of about 15 bar being set up.
After cooling to room temperature and decompression to atmospheric
pressure, the volatile constituents are distilled off and the
residue is taken up in water. The pH is then adjusted to 5 with
concentrated hydrochloric acid, and the precipitate which forms is
isolated by filtration. 50.3 g (0.22 mol; 88% of theory) of
D,L-2-aminotridecanoic acid are obtained.
Example 4
D,L-n-undecylglycine-N,N-diacetic acid
[0094] 57.3 g (0.25 mol) of 2-aminotridecanoic acid from Example 3
are added to a mixture of 250 g of water and 100 g of ethanol in a
steel autoclave. 51 g (0.51 mol) of a 30% strength formaldehyde
solution are added to this at room temperature under atmospheric
pressure. The mixture is then stirred for 1 h, before the reactor
is closed and heated to 100.degree. C. A pressure of about 4 bar is
set up and, under this, 75.7 g (0.51 mol) of a 33% strength sodium
cyanide solution are metered in. The mixture is stirred further
under the above conditions for 3 h until no further change in the
cyanide content can be found by titration. The pH is adjusted to 13
with 50% strength sodium hydroxide solution, after which hydrolysis
is continued under superatmospheric pressure for 6 h. After cooling
and decompression to atmospheric pressure, the volatile
constituents are distilled off and the residue is taken up in
water. The pH is adjusted to 2 with concentrated hydrochloric acid,
and the precipitate which forms is isolated by filtration. 83.2 g
(0.23 mol) of 95 % pure D,L-n-undecylglycine-N,N-diacetic acid with
a calcium binding capacity of 2.75 mmol/g are obtained,
corresponding to a yield of 92% of theory.
Example 5
D,L-n-undecylglycinonitrile-N,N-diacetonitrile
[0095] A suspension of 71.3 g (0.75 mol) of 99% pure
iminodiacetonitrile in 150 g of water and 100 g of methanol in a
steel autoclave is adjusted to pH 1.0 with 7.5 g of 50% strength
sulfuric acid. 31 g (1.14 mol) of hydrocyanic acid are added
dropwise to this at room temperature, before the autoclave is
closed and warmed to 35 to 40.degree. C. 142.5 g (0.75 mol) of 97%
pure lauraldehyde in 50 g of methanol are metered in by a diaphragm
pump over the course of 1.5 h. The mixture is heated to 100.degree.
C. and stirred at the same temperature under a pressure of about
3.5 bar for 8 hours until no further change in the hydrocyanic acid
content can be found by titration. After cooling to 10.degree. C.,
the phase containing the
D,L-n-undecyl-glycinonitrile-N,N-diacetonitrile which has formed is
separated from the aqueous phase, and all volatile constituents are
removed. Recrystallization from a little ethanol results in 192.7 g
(0.67 mol; 89% of theory) of trinitrile, whose purity is determined
by gas chromatography.
Example 6
D,L-n-undecylglycinonitrile-N,N-diacetonitrile
[0096] A suspension of 71.3 g (0.75 mol) of 99% pure
iminodiacetonitrile in 150 g of water and 100 g of methanol in a
steel autoclave is adjusted to pH 1.0 with 7.5 g of 50% strength
sulfuric acid. 23 g (0.83 mol) of hydrocyanic acid are added
dropwise to this at room temperature, before the autoclave is
closed and warmed to 35 to 40.degree. C. 142.5 g (0.75 mol) of 97%
pure lauraldehyde in 50 g of methanol are metered in by a diaphragm
pump over the course of 1.5 h. The mixture is heated to 130.degree.
C. and stirred at the same temperature under a pressure of about 6
bar for 6 hours until no further change in the hydrocyanic acid
content can be found by titration. After cooling to 10.degree. C.,
the phase containing the
D,L-n-undecyl-glycinonitrile-N,N-diacetonitrile which has formed is
separated from the aqueous phase, and all volatile constituents are
removed. Recrystallization from a little ethanol results in 197 g
(0.68 mol; 91% of theory) of trinitrile, whose purity is determined
by gas chromatography.
Example 7
D,L-n-undecylglycinonitrile-N,N-diacetonitrile
[0097] An emulsion of 48.0 g (0.5 mol) of 99% pure
iminodiacetonitrile and 9.0 g of sodium dodecyl sulfate in 185 g of
water is adjusted to pH 1.0 with 10.6 g of 50% strength sulfuric
acid. 19 g (0.7 mol) of hydrocyanic acid are added dropwise to this
at room temperature, before 95 g (0.5 mol) of 97% pure lauraldehyde
are metered in at 40.degree. C. over the course of 2 hours. The
mixture is heated to 70.degree. C. and stirred at the same
temperature for 6 hours until no further change in the hydrocyanic
acid content can be found by titration. Phase separation starts
during this reaction. After cooling to 10.degree. C., the phase
containing the trinitrile is separated from the aqueous phase and
recrystallized from a little ethanol. 124 g (0.43 mol; 86% of
theory) of D,L-undecylglycinonitrile are obtained, it being
impossible to remove the emulsifier completely, and its yield being
determined by gas chromatography.
Example 8
D,L-n-undecylglycinonitrile-N,N-diacetonitrile
[0098] 48 g (0.5 mol) of 99% pure iminodiacetonitrile, 95 g (0.5
mol) of 97% pure lauraldehyde, 1.6 g of p-toluenesulfonic acid
monohydrate and 19 g (0.7 mol) of hydrocyanic acid are mixed in a
flask with an efficient condenser at room temperature. The mixture
is slowly heated to 70.degree. C. and then stirred at this
temperature for 3 hours until no further change in the hydrocyanic
acid content can be found by titration. The crude reaction mixture
is added to water, and the organic phase is separated off and
recrystallized from a little ethanol. The yield of
D,L-undecylglycinonitrile-N,N-diacetonitrile is 127 g (0.44 mol;
88% of theory), determined by gas chromatography.
Example 9
D,L-n-undecylglycine-N-N-diacetic acid
[0099] The partially crystalline mixture from Example 5 is
introduced into 400 ml of ethanol in a steel autoclave. 536 g (2.68
mol) of 20% strength sodium hydroxide solution are added dropwise
to this, and the mixture is stirred at 30.degree. C. for 1 h. The
autoclave is closed and then heated to 10.degree. C., and
hydrolysis is continued at this temperature under a pressure of
about 4 bar for 6 h. After cooling to room temperature and
decompression to atmospheric pressure, the volatile constituents
are distilled off and the residue is taken up in water. The pH is
adjusted to 2 with concentrated hydrochloric acid, and the
precipitate which forms is isolated by filtration. 231 g (0.64 mol)
of 95% pure D,L-n-undecylglycinediacetic acid with a calcium
binding capacity of 2.75 mmol/g are obtained, corresponding to a
yield of 96% of theory (85% of theory based on
iminodiacetonitrile).
[0100] It is also possible to employ mixtures from Examples 6, 7 or
8 in place of the mixture from Example 5.
* * * * *