U.S. patent number 4,167,565 [Application Number 05/739,684] was granted by the patent office on 1979-09-11 for adenosine-5'-carboxamides and method of use.
This patent grant is currently assigned to Abbott Laboratories. Invention is credited to Anthony K. L. Fung, Raj N. Prasad, Herman H. Stein, Karin R. Tietje.
United States Patent |
4,167,565 |
Stein , et al. |
September 11, 1979 |
Adenosine-5'-carboxamides and method of use
Abstract
A method of controlling undesired animals including rodents,
coyotes and birds which comprises making available to said animals
an edible composition containing, as the active ingredient, a
lethal dose of a compound represented by formula ##STR1## wherein R
is H, loweralkyl or acetyl; R.sub.1 is H or acetyl; R.sub.2 is H,
Cl or NH.sub.2 ; R.sub.3 is H, loweralkyl, alkoxy, cycloalkyl or
hydroxyalkyl; R.sub.4 and R.sub.5 are each H, acetyl or propionyl,
or when taken together form a p-chlorobenzylidene, a carbonate or
an ethoxymethylene moiety; in a suitable carrier.
Inventors: |
Stein; Herman H. (Skokie,
IL), Prasad; Raj N. (Pierrefonds, CA), Tietje;
Karin R. (Philipsburg, CA), Fung; Anthony K. L.
(Pierrefonds, CA) |
Assignee: |
Abbott Laboratories (North
Chicago, IL)
|
Family
ID: |
24973363 |
Appl.
No.: |
05/739,684 |
Filed: |
November 8, 1976 |
Current U.S.
Class: |
514/46;
536/27.22; 536/27.62; 536/27.63 |
Current CPC
Class: |
C07H
19/16 (20130101) |
Current International
Class: |
C07H
19/16 (20060101); C07H 19/00 (20060101); A61K
031/52 (); C07H 019/16 () |
Field of
Search: |
;424/180 ;536/26,24 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Brown; Johnnie R.
Attorney, Agent or Firm: Niblack; Robert L. Fato; Gildo
E.
Claims
We claim:
1. A method of eliminating undesired animals selected from the
group consisting of rodents, coyotes and birds which are
economically or socially destructive to man, which method comprises
administering to said animals a lethal dose of a compound
represented by the formulae ##STR9## wherein R is H, loweralkyl of
1 to 6 carbon atoms or acetyl; R.sub.1 is H or acetyl; R.sub.2 is
H, Cl or NH.sub.2 ; R.sub.3 is H, loweralkyl of 1 to 6 carbon
atoms, alkoxy of no more than 6 carbon atoms, cycloalkyl of 3 to 8
carbon atoms or hydroxyalkyl of 1 to 6 carbon atoms; R.sub.4 and
R.sub.5 are each H, acetyl or propionyl, or when taken together
form a p-chlorobenzylidene, a carbonate or an ethoxymethylene
moiety; in a suitable carrier.
2. A method according to claim 1, wherein said lethal dose ranges
from 1 to 100 mg./kg. of body weight.
3. A method according to claim 1, wherein said compound is
represented by formula 1; each of R, R.sub.1, R.sub.2, R.sub.4 and
R.sub.5 is H; and R.sub.3 is --CH.sub.2 CH.sub.3.
4. A method according to claim 1, wherein said compound is
represented by formula 1; each of R, R.sub.1, R.sub.2, R.sub.4 and
R.sub.5 is H; and R.sub.3 is ##STR10##
5. A method according to claim 1, wherein said compound is
represented by formula 1; each of R, R.sub.1, R.sub.2, R.sub.4 and
R.sub.5 is H; and R.sub.3 is --CH(CH.sub.3).sub.2.
6. A method according to claim 1, wherein said compound is
represented by formula 1; each of R, R.sub.1 and R.sub.2 is H;
R.sub.3 is ##STR11## and each of R.sub.4 and R.sub.5 is acetyl.
7. A method according to claim 1, wherein said compound is
represented by formula 1; each of R, R.sub.1 and R.sub.2 is H;
R.sub.3 is --CH.sub.2 CH.sub.3 ; and each of R.sub.4 and R.sub.5 is
acetyl.
8. A method according to claim 1, wherein said compound is
represented by formula 1; each of R, R.sub.1 and R.sub.2 is H;
R.sub.3 is cyclobutyl; and each of R.sub.4 and R.sub.5 is
acetyl.
9. A method according to claim 1, wherein said compound is
represented by formula 1; each of R, R.sub.1 and R.sub.2 is H;
R.sub.3 is --CH.sub.2 CH.sub.3 ; and each of R.sub.4 and R.sub.5 is
propionyl.
10. A method according to claim 1, wherein said compound is
represented by formula 1; each of R, R.sub.1, and R.sub.2 is H;
R.sub.3 is --CH.sub.2 CH.sub.3 ; and R.sub.4 and R.sub.5 together
are ##STR12##
11. A method according to claim 1, wherein said compound is
represented by formula 1; each of R, R.sub.1 and R.sub.2 is H;
R.sub.3 is --CH.sub.2 CH.sub.3 ; and R.sub.4 and R.sub.5 together
are ##STR13##
12. A method according to claim 1 wherein R is H, CH.sub.3 or
acetyl, R.sub.1 is H or acetyl, R.sub.2 is H, Cl or NH.sub.2,
R.sub.3 is H, CH.sub.3, --CH.sub.2 CH.sub.3 --CH.sub.2 CH.sub.2 OH,
##STR14## or ethoxy, and R.sub.4 and R.sub.5 are each H, acetyl, or
##STR15##
13. A method according to claim 1 wherein said compound is
represented by formula 2 and R.sub.3 is --CH.sub.2 CH.sub.3 or
##STR16##
14. A compound of the formula ##STR17## wherein R, R.sub.1, R.sub.4
and R.sub.5 are each H, R.sub.2 is Cl or NH.sub.2 and R.sub.3 is
--CH.sub.2 CH.sub.3.
15. A compound of the formula ##STR18## wherein R.sub.3 is
--CH.sub.2 CH.sub.3 or ##STR19##
Description
BACKGROUND OF THE INVENTION
The present invention relates to undesired animals such as rodents,
coyotes and dangerous birds, and lethal drugs used for their
control. It is very necessary to have a means which is effective
and inexpensive to control these undesired animals.
Undesirable animals, e.g., rodents and particularly rats, are
responsible for extensive and serious damage to man's well-being.
They are known to consume and contaminate food supplies and to
destroy grain fields. In addition, they are known to carry and
transmit diseases, to create social nuisances, and to cause damage
to buildings. In the United States alone, it is a well-known fact
that the annual damage caused by pests results in a loss of
hundreds of millions of dollars. It is clear, therefore, that the
method of the present invention for the control of undesired
animals is a welcomed contribution.
In the past, poison chemicals have been used in the elimination of
such unwanted animals. However, such poison chemicals were easily
detected or so toxic that the undesirable animals would not ingest
a lethal dose. Therefore, it would be advantageous to have a drug
or material as provided by the present invention which is lethal to
these unwanted animals but still a drug or material is edible by
these undesirable animals.
DETAILED DESCRIPTION OF THE INVENTION
The present invention provides a method of controlling undesired
animals such as rodents, coyotes and dangerous birds. The method
comprises making available to the undesired animals an edible
composition containing, as the active component, a lethal dose of a
compound represented by the formula ##STR2## wherein R is H,
loweralkyl or acetyl; R.sub.1 is H or acetyl; R.sub.2 is H, Cl or
NH.sub.2 ; R.sub.3 is H, loweralkyl, alkoxy, cycloalkyl or
hydroxyalkyl; R.sub.4 and R.sub.5 are each H, acetyl or propionyl,
or when taken together form a p-chlorobenzylidene, a carbonate or
an ethoxymethylene moiety; and a suitable carrier.
The term "undesired animals", as used herein, refers to undesirable
rodents, coyotes and birds which are economically and socially
destructive to man. More specifically, the term "undesired animals"
refers to undesirable rodents such as rats, mice, ground squirrels,
prairie dogs, pocket gophers, rabbits, nutria, and the like;
coyotes; and undesirable birds, such as pigeons, starlings,
blackbirds, grackles, cowbirds, crows, and the like.
As used herein, the term "loweralkyl" refers to C.sub.1 -C.sub.6
straight or branched chain alkyl groups including methyl, ethyl,
n-propyl, iso-propyl, n-butyl, sec-butyl, tert-butyl, n-pentyl,
iso-pentyl, neo-pentyl, n-hexyl and the like.
The term "alkoxy" refers to alkoxy groups having a total of no more
than 6 carbon atoms such as methoxy, ethoxy, n-propoxy, iso-propoxy
and the like.
"Cycloalkyl" as used herein, refers to cyclic saturated aliphatic
radicals having three to eight carbon atoms in a ring, such as
cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and
cyclooctyl.
The term "hydroxyalkyl" refers to hydroxyalkyl groups having from 1
to 6 carbon atoms, such as hydroxymethyl, hydroxyethyl,
hydroxypropyl, hydroxybutyl, hydroxypentyl, hydroxyhexyl and the
like.
The present invention includes within its scope lethal compositions
comprising, as an active ingredient, at least one of the compounds
of this invention in association with an acceptable carrier or
diluent.
Liquid dosage forms for oral administration include acceptable
emulsions, solutions, suspensions, syrups and elixirs containing
inert diluents commonly used in the art, such as water. Besides
inert diluents, such compositions can also include adjuvants, such
as wetting agents, emulifying and suspending agents and flavoring
agents.
The compounds of this invention exhibit a lethal effect on
undesired animals at a dose ranging from 1 to 100 mg./kg. body
weight. A lethal dose (oral LD.sub.50) for mice ranges from about
10 to 50 mg./kg.; for rats from 0.5 to 10 mg./kg.; for coyotes from
5.0 to 10 mg./kg.; and for birds from 0.5 to 10 mg./kg.
The present compounds may be prepared by means of various methods
and processes. For example, compounds represented by formula 1
##STR3## wherein each of R, R.sub.1 and R.sub.2 is H; R.sub.3 is H,
alkyl, cycloalkyl or hydroxyalkyl; and each of R.sub.4 and R.sub.5
is H or acetyl, can be prepared according to the process described
in U.S. Pat. 3,864,483. Also, the compounds of formula (1) wherein
each of R, R.sub.1, R.sub.2, R 4 and R.sub.5 is H; and R.sub.3 is
alkoxy, can be prepared according to the method described in U.S.
Pat. No. 3,855,206.
Moreover, the preparations of compounds of formula 1 wherein R is
H, alkyl or alkoxy; R.sub.1 is H or alkyl; R.sub.2 is H; R.sub.3 is
loweralkyl or cycloalkyl; and where each of R.sub.4 and R.sub.5 is
H, alkoxy, or when taken together form a p-chlorobenzylidene, a
carbonate or an ethoxymethylene moiety, are described in the
Examples herein-below.
In addition, compounds of formula 2 ##STR4## where R.sub.3 is alkyl
or cyclopropyl, may be prepared according to the processes
described in the Examples herein-below.
According to the present invention, the compounds that are lethally
effective against undesired animals include compounds of formula
1:
(3) Adenosine-4'-carboxamide
(4) Adenosine-5'-[(N-methyl)-carboxamide]
(5) Adenosine-5'-[(N-ethyl)-carboxamide]
(6) Adenosine-5'-[(N-isopropyl)-carboxamide]
(7) Adenosine-5'-[(N-cyclopropyl)-carboxamide]
(8) N.sup.6 -methyl-adenosine-5'-[(N-ethyl)-carboxamide]
(9) N.sup.6 -methyl-adenosine-5'-[(N-cyclopropyl)-carboxamide] (10)
Adenosine-5'-[N-(2-hydroxyethyl)carboxamide]
(11) 2',3'-Diacetyl-adenosine-5'-[(N-cyclopropyl)-carboxamide]
(12) 2',3'-Diacetyl-adenosine-5'-[(N-ethyl)carboxamide]
(13) Adenosine-5'-[(N-cyclobutyl)carboxamide]
(14) 2',3',N.sup.6
-tripropionyl-adenosine-5'-[(N-ethyl)-carboxamide]
(15) 2',3', N.sup.6,N.sup.6 -tetra-acetyl
adenosine-5'-[(N-cyclopropyl)carboxamide]
(16)Adenosine-5'-[(N-methoxy)carboxamide]
(17)
2',3'-(O-ethoxymethylene)-adenosin-5'-[N-ethyl)-carboxamide]
(18) 2-chloroadenosine-5'-[(N-ethyl)-carboxamide]
(19) 2-Amino adenosine-5'-[(N-ethyl)-carboxamide]
(20) Adenosine-5-[(N-ethyl)-carboxamide]-2',3'-carbonate
(21)
2',3'-0-(4-chlorobenzylidene)-adenosine-5'-[(N-ethyl)carboxamide]mono
hydrochloride
and compounds of formula 2:
(22) Adenosine-5'-[(N-ethyl)carboxamide]-N'-oxide; and
(23) Adenosine-5'-[(N-cyclopropyl)carboxamide]-N'-oxide.
In practicing the present method for controlling undesired animals,
the active compound may be incorporated into a food complement with
or without baits. The drug can, for example, be incorporated into a
food complement and/or bait by any convenient manner, as for
instance, by simply mixing in the case of solid materials and by
dissolution or suspension in the case of liquid materials. Thus,
for example, the lethal drug is admixed in corn, oats, rye, wheat,
bran or grass, legumes, milk, meat, fish or other nutrients, as
well as mixtures thereof, or together with conventional baits,
e.g., sugar molasses, corn oil, peanut oil, peanut butter, bacon,
lard, mutton, tallow, and the like, as well as mixtures
thereof.
The amount of drug employed in the edible compositions of the
present invention can vary considerably. In order to control or
regulate the amount of the edible composition that will be consumed
by each member of a group of undesired animals, it is preferred to
use as large an amount of the control chemical in the composition
as possible without causing the composition to be objectionable to
the undesired animals. This amount, i.e., the highest
concentration, will vary with the particular animal being
controlled and with the type of bait being used. Ordinarily, the
amount of the lethal drug varies from about 0.0001 to about 0.5
percent by weight of the novel edible composition. However, amounts
above or below this range can be used, if desired, depending on
such factors as the type of animal being controlled.
In the case of controlling coyotes, a toxic collar program may also
be used according to the present invention. According to this
program, a toxic collar is placed around the neck of the sheep or
animal which the coyotes generally attack. The toxic collar is
composed of plastic packets which each contain a toxicant, i.e., a
lethal amount of a drug in a suitable carrier. In the process of
attacking a sheep, or any other animal wearing such a collar, a
coyote self-administers a lethal dose of the drug by biting into
the packets of the collar.
The following examples further illustrate the present
invention.
EXAMPLE 1
2',3'-(O-ethoxymethylene)-adenosine-4'-[(N-ethyl)carboxamide]
A mixture of adenosine-5'-(N-ethyl)carboxamide (3.0 g.) in dry DMF
(40 ml.) containing ethyl orthoformate (6 ml.) was mixed with a
solution of dry HCl (2.3 ml. of 5.6N solution of HCl in dry DMF).
The clear solution was stirred (26 hours) at the room
temperature.
At the end of this period, triethylamine (2 ml.) was added to the
reaction mixture, stirred and filtered.
The filtrate was evaporated, and after the removal of
triethylamine, DMF was distilled under high vacuum in a
40.degree.-50.degree. C. bath. The white solid residue was
dissolved in a mixture of ethyl acetate:CHCl.sub.3 (4:1) and the
solution was filtered and concentrated to give 3.0 g. of
2',3'-O-ethoxymethylene adenosine-4'-(N-ethyl) carboxamide, melting
at 150.degree.-151.degree..
Analysis Calcd. for C.sub.15 H.sub.20 N.sub.6 O.sub.5 : C, 49.44;
H, 5.53; N, 23.06 Found: C, 48.90; H, 5.79; N, 22.67
EXAMPLE 2
2-Chloroadenosine-5'-(N-ethyl)carboxylate
An aqueous solution of KMnO.sub.4 (2.2 g.; 0.014 mole); in 60 ml.
H.sub.2 O was added dropwise (3.5 hours) to a stirred suspension of
2-chloro-2',3'-O-isopropylidene adenosine (1.5 g., 0.0045 mole) in
water (320 ml.) containing KOH (0.784 g., 0.014 mole), at the room
temperature. The reaction mixture was stirred for 20 hours, then
decolorized by the dropwise addition of H.sub.2 O.sub.2 (5 ml. of
30% H.sub.2 O.sub.2 in 20 ml. of H.sub.2 O) at 5.degree.-10.degree.
C. and filtered through celite. The colorless filtrate was
concentrated in vacuo (at 35.degree.-40.degree. C.) to 20 ml. and
acidified (pH 4) with HCl. The white precipitate was filtered,
successively washed with water, acetone and ether to give 1.2 g.
(75%) of 2-chloro-2',3'-O-isopropylidene adenosine-5'-carboxylic
acid, melting at 262.degree.-63.degree. C., R.sub. f 0.72
(isopropanol--NH.sub.4 OH--H.sub.2 O; 7:1:2).
A mixture of 2-chloro-2',3'-O-isopropylidene
adenosine-5'-carboxylic acid (1.2 g, 0.0033 mole) in 50% HCOOH (70
ml.) was stirred (1.5 hours) at 70.degree.-80.degree. C. The
solution was evaporated under reduced pressure (at
30.degree.-40.degree. C.); residue diluted with water and
evaporated again. This process was repeated several times until
there was no odor of formic acid in the residue. The residue,
2-chloroadenosine-5'-carboxylic acid, (0.8 g., 80%) was dried
overnight at 60.degree. C., in vacuo over P.sub.2 O.sub.5 ; m.p.
>300.degree. C., ir (KBr) 1710 cm.sup.-1 ; R.sub.f 0.51
(isopropanol--NH.sub.4 OH--H.sub.2 O 7:1:2).
The dried 2-chloroadenosine-5'-carboxylic acid (0.70 g., 0.022
mole) was stirred in absolute ethanol (100 ml.) at 5.degree. C. and
SOCl.sub.2 (0.8 ml.) was added dropwise. After a few minutes a
clear solution was obtained, but about an hour later (at
5.degree.-10.degree. C.) there was separation of a solid. Stirring
was continued overnight at the room temperature. The reaction
mixture was then diluted with dry ether (50 ml.) and filtered to
give 0.8 g. (95%) of a white powder melting at
132.degree.-39.degree. C. Recrystallization from ethanol-benzene
gave the flocculent white ester (ir 1730 cm.sup.-1, m.p.
150.degree.-55.degree. C. dec.); R.sub.f 0.76 (CHCl.sub.3 --MeOH;
(6:1); NMR (DMSO--d.sub.6).delta. 8.73 (H.sub.8), 7.36 (6--NH.sub.2
+2',3'--OH), 1.23 ##STR5## Mass spectra gave the molecular ion peak
at m/e 343 and the fragmentation pattern was consistent with the
structure of 2-chloro-adenosine-5'-(ethyl)-carboxylate.
Analysis Calcd, for C.sub.12 H.sub.14 ClN.sub.5 O.sub.5.HCl: C,
37.91; H, 3.98; Cl, 18.65; N, 18.42; O, 21.04 Found: C, 37.61; H,
4.05; Cl, 18.66; N, 18.34; O, 21.10
EXAMPLE 3
2-Chloroadenosine-5'-(N-ethyl)carboxamide (18)
An aqueous solution of 2-chloro-adenosine-5'-(ethyl)-carboxylate
was basified with aqueous NaHCO.sub.3 and the precipitate was
filtered, washed with water and dried overnight in vacuo over
P.sub.2 O.sub.5. The dried material (1.6 g.) was added to liquid
ethyl amine (60 ml.) cooled in dry-ice. After stirring for three
hours at -20.degree. C., the reaction mixture was slowly allowed to
warm up to the room temperature and then left at this temperature
for twenty hours. The solid residue left, was stirred with ethanol,
filtered and washed with dry ether to give 1.5 g. (94%) of the
amide, 2-chloroadenosine-5'-(N-ethyl)carboxamide, melting at
245.degree.-247.degree. C. dec. After washing with boiling ethanol,
the m.p. of the product was 250.degree.-251.degree. C., R.sub.f
0.29 (CHCl.sub.3 --MeOH; 6:1)
Analysis Calcd. for C.sub.12 H.sub.15 ClN.sub.6 O.sub.4 : C, 42.02;
H, 4.41; N, 24.50 Found: C, 41.91; H, 4.47; N, 24.42
EXAMPLE 4
2-Amino-Adenosine-5'-(N-ethyl)carboxamide (19)
2,6-Diacetamido-9-(tri-O-acetyl-.beta.-D-ribofuranosyl)purine
Dry HCl gas was passed through a mixture of dry
1,2,3,5-tetra-O-acetyl-.beta.-D-ribofuranoside (20.4 g, 0.064 mole)
in anhydrous ether (400 ml.) at 5.degree. C., until a clear
solution was obtained (11/4 hours). The solution was stirred at the
room temperature for 90 minutes and then evaporated in vacuo. The
residual oil was mixed with CCl.sub.4 and evaporation continued.
This process was repeated a few times, under anhydrous conditions.
The residual liquid was taken up in freshly distilled xylene and
refluxed with chloromercuri-2,6-diacetamido purine (30 g., 0.064
mole, dried by keeping in vacuo for twenty-four hours over P.sub.2
O.sub.5 and then by refluxing with xylene until no more water
separated in the Dean-Stark receiver) for four hours and then left
overnight at the room temperature. The residue was extracted
several times with warm dry CHCl.sub.3, and the extract was washed
(as usual), dried and stirred with charcoal, filtered and
evaporated in vacuo to give nearly colorless powder (16.0 g.,
51.5%) instead of a glass; m.p. 87.degree.-92.degree. C.,
.delta.max (MeOH) in nm 226, 269, NMR (CDCl.sub.3 -d.sub.6)
.delta.9.8 (NH), 9.35 (NH), 8.35 (H.sub.8), 7.3 (NH.sub.2), 6-5
(2',3',5'--OH), 2.3 (CH.sub.3 -C.dbd.O).
2-Acetamido-2',3'-O-isopropylidene adenosine
The Z-acetamido-adenosine used in this preparation was prepared
from 2,6-diacetamido-9-(tri-O-acetyl-.beta.-D-ribofuranosyl)purine
by the method described by Davoll and Lowy, J. Amer. Cham. Soc.,
73, 1650 (1951). A suspension of 2-acetamido adenosine (7.3 g;
0.0225 mole) in dry acetone (1.5.1) was mixed with p-toluene
sulfonic acid monohydrate (43 g., 0.0225 mole) and stirred. A clear
solution which resulted immediately gave heavy precipitate in five
minutes. After stirring for fifteen minutes at room temperature,
solid NaHCO.sub.3 (70 g.) was added and stirring was continued for
another twenty-four hours. The solids were separated by filtration
and filtrate was evaporated to dryness. The residue on trituration
with ether gave 6.7 g. (82%) of 2-acetamido-2',3'-O-isopropylidene
adenosine, melting at 197.degree.-203.degree. C.; R.sub.f 0.56
(CHCl.sub.3 --MeOH; 9:1); .lambda.max (MeOH) in nm: 226; 271; NMR
(DMSO-d.sub.6).delta.9.9 (NH), 8.25 (H.sub.8), 7.3 (NH.sub.2), 2.3
(CH.sub.3 CO), 1.3 & 1.5 (2CH.sub.3).
2-Acetamido-2',3'-O-isopropylidene adenosine-5'-carboxylic acid
Powdered 2-acetamido-2',3'-O-isopropylidene adenosine (2.5 g.,
0.00687 mole) was suspended in warm water (400 ml.) and cooled to
room temperature. Aqueous KOH (1.15 g., 0.0206 mole in 30 ml.
H.sub.2 O) was added, with stirring, followed by a slow addition
(1.5 hour) of KMnO.sub.4 (4.3 g. in 100 ml. H.sub.2 O) at room
temperature. Excess KMnO.sub.4 was destroyed by the dropwise
addition of 20% H.sub.2 O.sub.2 (at 5- 10.degree. C.) until there
was no more pink color. The precipitated MnO.sub.2 was removed by
filtration through celite. The clear filtrate was brought to pH 7
to 7.5 and then evaporated to near dryness below 40.degree. under
reduced pressure. The pH was then adjusted to 5-6 by dilute HCl and
the solution was evaporated to dryness under reduced pressure. The
residue was repeatedly extracted with boiling absolute ethanol. The
ethanol extract on evaporation gave 2.0 g. (77%) of
2-acetamido-2',3'-O-isopropylidene adenosine-5'-carboxylic acid
having an indefinite melting point (160.degree. C. . . 176.degree.
C. . . 197.degree. C. dec.). In order to confirm the structure of
the acid .lambda.max (MeOH) in nm; 225, 271), it was converted into
its ethyl ester as described below.
A mixture of 2-acetamido-2',3'-O-isopropylidene
adenosine-5'-carboxylic acid (0.4 g., 0.00105 mole) in absolute
ethanol (60 ml.) and SOCl.sub.2 (0.5 ml.) at room temperature, was
stirred for fifteen hours and then evaporated to dryness under
reduced pressure below 30.degree. C. The residue was dissolved in
aqueous NaHCO.sub.3 solution at 10.degree. C. and the basic
solution was extracted successively with CHCl.sub.3 and ethyl
acetate. The organic extracts were combined, dried and evaporated
to dryness and recrystallized from absolute ethanol to give 0.64 g.
(15%) of 2-acetamido-2',3'-O-isopropylidene
adenosine-5'-(ethyl)-carboxylate melting at 221.degree.-222.degree.
C. having the characteristic ir peak at 1740 cm.sup.-1 ;
.lambda.max (MeOH) in nm 225, 271; NMR (DMSO-d.sub.6).delta. 9.77
(NH), 8.16 (H.sub.8), 7.20 (NH.sub.2), 2.16 (CH.sub.3 --CO), 1.53,
##STR6##
Analysis Calc. for C.sub.17 H.sub.22 N.sub.6 O.sub.6 : C, 50.24; H,
5.46; N, 20.68 Found: C, 50.31; H, 5.59; N, 20.88
2-Acetamido adenosine-5'-carboxylic acid
A solution of 2-acetamido-2',3'-O-isopropylidene
adenosine-5'-carboxylic acid (2.0 g., 0.0053 mole) in 50% formic
acid (80 ml.) was kept at 70.degree. C. for seventy-five minutes
and then evaporated to dryness under reduced pressure. The residue
was mixed with a little water and evaporated again. This process
was repeated a few times to give 0.8 g. (45%) of 2-acetamido
adenosine-5'-carboxylic acid, melting at 295.degree. C. Infra red
spectra (KBr) showed the characteristic 1715 cm.sup.-1 peak. The
compound was insoluble in every solvent except aqueous base.
.lambda.max (0.1 N HCl+MeOH) in nm 215, 266.
Analysis Calcd. for C.sub.12 H.sub.14 N.sub.6 O.sub.6 : C, 42.61;
H, 4.17; N, 24.84 Found: C, 41.83; H, 4.40; N, 24.59
2-Amino adenosine-5'-carboxylic acid
A mixture of 2-acetamido-2',3'-O-isopropylidene
adenosine-5'-carboxylic acid (1.0 g., 0.0026 mole) in 1N HCl was
kept at 60.degree.-65.degree. C. for thirty minutes. The reaction
mixture was cooled, then basified with 50% NaOH and acidified with
acetic acid. The precipitate was filtered, washed successively with
water and ethanol to give 0.2 g. (23%; m.p. 228.degree. C.) of 2
-amino -adenosine-5'-carboxylic acid; .lambda.max (MeOH) in nm 223,
248 and 278.
2-Amino adenosine-5'-(ethyl) carboxylate
Thionyl chloride (2.5 ml.) was added dropwise to a suspension of
2-acetamido-adenosine-5'-carboxylic acid (2.5 g., 0.0074 mole) in
absolute ethanol (120 ml.) at 0.degree. C. After an hour at
0.degree. C., the reaction mixture was stirred overnight at the
room temperature. The mixture was cooled, diluted with ether and
filtered to give 1.9 g. of 2-amino adenosine-5'-(ethyl) carboxylate
as a hydrochloride salt. The salt was dissolved in water and
basified with NaHCO.sub.3 solution, filtered, washed successively
with water, ethanol, ether and dried in vacuo over P.sub.2 O.sub.5
to give 1.2 g. (44%) of 2-amino-adenosine-5'-(ethyl) carboxylateas
a monohydrate melting at 215.degree.-216.degree. C. dec.; ir (KBr)
1740 cm.sup.-1 ; .lambda.max (meOH) in 221, 258, 278; NMR
(DMSO-d.sub.6).delta. 8.08 (H.sub.8), 6.86 (NH.sub.2), 5.8
(NH.sub.2, 2',3'-OH), ##STR7## A molecular ion peak at 324 and a
fragment at m/e 150 confirmed the structure of 2-amino
adenosine-5'-(ethyl) carboxylate.
Analysis Calcd. for C.sub.12 H.sub.16 N.sub.6 O.sub.5.H.sub.2 O: C,
42.11; H, 5.30; N, 24.55 Found: C, 42.07; H, 4.78; N, 24.55
2-Acetamido adenosine-5'-(ethyl) carboxylate
In the preceding reaction, the mother liquor, after the removal of
1.2 g. of 2-amino adenosine-5'-(ethyl) carboxylate, was evaporated
to dryness at 30.degree. C. under reduced pressure. The residue was
washed with ether and then stirred with aqueous NaHCO.sub.3
solution. The insoluble material, 2-acetamido adenosine-5'-(ethyl)
carboxylate (0.147 g., m.p. 252.degree.-255.degree. C. dec.) had
the characteristic ir peaks: 1745 cm.sup.-1, 1720 cm.sup.-1 and
1650 cm.sup.-1 ; .lambda.max (MeOH) in nm 225, 271; R.sub.f 0.76
(n-butanol-acetic acid-H.sub.2 O; 5:2:3); NMR
(DMSO-d.sub.6).delta.9.89 (NH), 8.23 (H.sub.g), 7.23 (NH.sub.2),
6.0-5.5 (2',3'-OH), ##STR8##
Analysis Calcd. for C.sub.14 H.sub.18 N.sub.6 O.sub.6 : C, 45.90;
H, 4.95; N, 22.94 Found: C, 45.59; H, 4.96; N, 23.06
2-Amino adenosine-5'-(N-ethyl) carboxamide (19)
The ester, 2-amino adenosine-5'-(ethyl) carboxylate, (1 g., 0.00292
mole) was added to liquid monothylamine (.apprxeq.20 ml.). The
clear solution was allowed to warm up to the room temperature and
stirred under N.sub.2 until the excess of the amine evaporated off.
Absolute ethanol was added to the residue and the mixture was
evaporated in vacuo. The residue, on two recrystallization from
absolute ethanol, gave 1.0 g. (m.p. 113.degree.. . .
120.degree.-23.degree. dec) of the product (19).
Analysis Calcd. for C.sub.12 H.sub.17 N.sub.7 O.sub.4 .0.5EtOH: C,
44.11; H, 5.92; O, 21.15 Found: C, 44.07; H, 6.14; O, 21.21
The structure was confirmed by NMR.
EXAMPLE 5
Adenoisine-5'-(N-ethyl) carboxamide
2',3'-isopropylidene adenosine-5'-carboxylic acid and
thionylchloride was stirred with excess of dry liquid ethyl amine
at -50.degree. to -35.degree. C. The clear orange-red solution was
slowly allowed to warm up to the room temperature, and then kept
for fifteen hours at the room temperature under anhydrous
conditions. At the end of the period (when most of the excess ethyl
amine had evaporated off) the residue was stirred with cold aqueous
NaHCO.sub.3 solution at 0.degree. C., filtered and washed with a
small amount of ice-cold water to give 3.1 g. of
2',3'-O-isopropylidene adenosine-5'-(N-ethyl) carboxamide; m.p.
225.degree.-227.degree.); R.sub.f 0.72 (silica gel), system;
n-BuOH:H.sub.2 O:NH OH (86:14:5). The crude amide was heated with
80 ml. 1N HCl at 65.degree. for forty-five minutes. The acidic
solution was cooled, basified with NaHCO.sub.3 and evaporated to
dryness under reduced pressure. The residue was recrystallized
twice from ethanol and finally from a small amount of water. The
white crystalline product was dried (70.degree.-80.degree.) in
vacuo over P.sub.2 O.sub.5 for forty-eight hours to give 0.1 g.
(32%) of adenosine-5'-(N-ethyl) carboxamide (5), which melted
slowly above 136.degree. and solidified again at
148.degree.-150.degree. and finally melted again at
246.degree.-247.degree.; [.alpha.].sub.D.sup.26 -163.degree. (c,
0.92 in 1N HCl); R.sub.f 0.51 (silica gel), system; n-BuOH:H.sub.2
O; NH.sub.4 OH (86:14:5). Elemental analysis and NMR data confirmed
the identity of the product (5).
EXAMPLE 6
Adenosine-5'-[(N-ethyl)carboxamide]-2',3'-carbonate (20)
A mixture of adenosine-5'-(N-ethyl) carboxamide (5) (2.0 g., 0.0065
mole) and 1,1'-carbonyldiimidazole (4.0 g., 0.024 mole) in dry DMF
(35 mole) was stirred at the room temperature. After four hours,
the reaction mixture was diluted with ether containing a little
petroleum ether (30.degree.-60.degree. ). The gummy precipitate was
triturated with cold ethanol and the product (m.p.
226.degree.-230.degree. ) was filtered. Two recrystallizations from
ethyl acetate gave 1.0 g. of the product (20) melting at
235.degree.-236.degree. C.
Analysis Calcd. for C.sub.13 H.sub.14 N.sub.6 O.sub.5 : C, 46.71;
H, 4.22; N, 25.14 Found: C, 46.40; H, 4.23; N, 24.97
EXAMPLE 7
Adenosine-5'-(N-cyclopropyl) carboxamide N.sup.1 -oxide (23)
Hydrogen peroxide (11 ml. of 30% H.sub.2 O.sub.2) was added to a
suspension of 3.2 g. of adenosine-5'-(N-cyclopropyl) carboxamide
(7, prepared as described before) in glacial acetic acid (100 ml.).
The clear solution was left at the room temperature for four days.
At the end of this period, the mixture was cooled to 0.degree. C.
stirred with 5% Pd/C (1.0 g.) for 0.5 hours and then at
10.degree.-15.degree. C. for another thirty minutes, and finally
filtered through celite and charcoal. The residue was washed with
methanol and the filtrate was concentrated under reduced pressure.
The residual liquid was successively diluted with methanol,
methanol and benzene, benzene and was evaporated each time under
reduced pressure to give a viscous mass. Trituration of the latter
with acetone/ether gave the product as a pinkish white solid.
Two recrystallizations from ethanol/benzene gave 2.5 g. of
adenosine-5'-(N-cyclopropyl) carboxamide-N.sup.1 -oxide melting at
195.degree.-197.degree.; [.alpha.].sub.D.sup.26 -10+11.degree. (c=
0.95 in 1N.HCl).
Analysis Calcd. for C.sub.13 H.sub.16 N.sub.6 O.sub.5 : C, 46.49;
H, 4.76; N, 25.00 Found: C, 46.09; H, 4.66; N, 24.44
The structure was confirmed by NMR.
EXAMPLE 8
Adenosine-5'-(N-ethyl) carboxamide-N.sup.1 -oxide (22)
Adenosine-5'-(N-ethyl) carboxamide-N.sup.1 -oxide was prepared
according to the method described above in Example 7. Starting from
adenosine-5'-(N-ethyl) carboxamide (3.1 g.), in glacial acetic acid
and 30% H.sub.2 O.sub.2, 1.8 g. (57%) of the corresponding N.sup.1
-oxide was obtained, melting at 237.degree.-238.degree..
Recrystallization from ethanol/ether gave pure
adenosine-5'-(N-ethyl) carboxamide-N.sup.1 -oxide melting at first
over 185.degree., resolidified and then melts again at 240.degree.
decomp.; R.sub.f 0.23 (n-BuOH:H.sub.2 O:NH.sub.4 OH --
86:14:5).
Analysis Calcd. for C.sub.12 H.sub.16 N.sub.6 O.sub.5 : C, 44.44;
H, 4.93; O, 24.69 Found: C, 44.08; H, 5.17; O, 24.31
EXAMPLE 9
N.sup.6 -Methyl adenosine-5'-(N-ethyl) carboxamide (8)
A solution of 2',3'-O-isopropylidene adenosine-5'-carboxylic acid
(9.6 g., 0.03 mole) at 60.degree.-70.degree. in dry DMF (600 ml.)
was cooled to 30.degree., methyl iodide (21.3 g., 0.15 mole) was
added and the mixture was stirred under nitrogen. After six days at
30.degree. C., the reaction mixture was poured into five liters of
1:5 mixture of ether:petroleum ether (30.degree.-60.degree. ). The
mixture was stirred and then left overnight at
0.degree.-10.degree.. The supernatant liquid was decanted off the
residue and triturated several times with petroleum ether. Finally,
the washed residue was dissolved in water (300 ml.), basified wth
concentrated NH.sub.4 OH (15 ml.) and heated over a steambath for
two hours. The reaction mixture was then concentrated (150 ml. or
less) under reduced pressure, cooled, acidified (pH 4-5) with
glacial acetic acid. The precipitated N.sup.6
-methyl-2',3'-O-isopropylidene adenoisine-5'-carboxylic acid was
filtered, washed with a small amount of cold water and dried at
60.degree. in vacuo over P.sub.2 O.sub.5 for eight hours.
Yield 7.0 g. (70%; m.p. 223.degree.-25.degree. dec.); R.sub.f 0.20
(system; n-BuOH:AcOH:water; 4:1:5).
The dried N.sup.6 -methyl-2',3'-O-isopropylidene
adenosine-5'-carboxylic (4.5 g.) was added, portionwide, to stirred
SOCl.sub.2 (40 ml.) at 0.degree. C. After the addition was
completed, the reaction mixture was stirred for two hours at the
room temperature. The clear yellow reaction solution was then
poured onto well stirred ether (400 ml.). The precipitated N.sup.6
-methyl-2',3'-O-isopropylidene adenosine-5'-carboxylic acid
chloride was filtered, washed with plenty of dry ether (until free
from SOCl.sub.2) and then added to an excess of liquid ethyl amine
at -30.degree. C. The reaction mixture was stirred (24 hours) and
was allowed to warm up slowly to the room temperature. The reaction
mixture was evaporated to dryness, basified with aqueous
NaHCO.sub.3 solution and extracted with CHCl.sub.3. The dry
CHCl.sub.3 extract was evaporated to give 2.9 g. of N.sup.6
-methyl-2',3'-O-isopropylidene adenosine-5'-(N-ethyl) carboxamide,
melting at 80.degree. with foaming; R.sub.f 0.59 (n-butanol-conc.
NH.sub.4 OH: H.sub.2 O; 86:5:14).
The pure N.sup.6 -methyl-2',3'-O-isopropylidine
adenosine-5'-(N-ethyl)carboxamide (2.9 g.) was mixed with formic
acid (60 ml. of 50%) and kept at the room temperature until 14
days, when the hydrolysis was completed (TLC). At the end of this
period, the reaction mixture was evaporated to dryness. The residue
was triturated several times with ether and then dissolved in
absolute ethanol and filtered (norit). The filtrate, on dilution
with ether gave some precipitate. The precipitate was discarded,
the filtrate was evaporated to dryness and the residue was dried in
vacuo at the room temperature over P.sub.2 O.sub.5 for 72 hours to
give pure N.sup.6 -methyl adenosine-5'-(N-ethyl)-carboxamide (8) in
35% yield; m.p. 130.degree.-31.degree.; [.alpha.].sub.D.sup.26 =
23.degree. .+-.1.1.degree. (c= 0.17 in 1N.HCl); R.sub.f 0.52
(n-BuOH:NH.sub.4 OH:H.sub.2 O; 86:5:14).
Analysis Calcd. for C.sub.13 H.sub.18 N.sub.6 O.sub.4 : C, 48.49;
H, 5.62; N, 26.06; O, 19.83 Found: C, 47.88; H, 5.96; N, 26.89; O,
20.24
The structure was confirmed by the NMR spectra.
EXAMPLE 10
N.sup.6 -Methyl adenosine-5'-(N-cyclopropyl) carboxamide (9)
N.sup.6 -Methyl adenosine-5'-(N-cyclopropyl) carboxamide (9) was
prepared according to the method described above, in Example 9.
Thus, the intermediate, N.sup.6 -methyl-2',3'-O-isopropylidene
adenosine-5'-(N-cyclopropyl) carboxamide was obtained from N.sup.6
-methyl-2',3'-O-ixopropylidene adenosine-5'-carboxylic acid in 52%
yield, melting at 85.degree.-88.degree. (THFpetroleum ether);
R.sub.f 0.63 [same system as for N -methyl-2',3'- O-isopropylidene
adenosine-5'-(N-ethyl)carboxamide].
The carboxamide was hydrolyzed for 12 days (TLC) with 50% HCOOH, as
before. The residue, after evaporation of the reaction mixture, was
purified twice by solution in acetone with the help of a little
ethanol (norit) to give pure N -methyl adenosine-5'-(N-cyclopropyl)
carboxamide (9) in 28% yield, melting at 128.degree.-133.degree.
(foams); R.sub.f 0.53 same as above system. The compound (9) had
the desired IR and NMR spectra.
Analysis Calcd. for C.sub.14 H.sub.18 N.sub.6 O.sub.4 : C, 50.29;
H, 5.42; N, 25.14; O, 19.14 Found: C, 50.08; H, 5.73; N, 24.90; O,
19.25
EXAMPLE 11
Adenosine-5'-(.beta.-chloroethyl) carboxylate
Thionyl chloride (4.5 ml.) was added to a stirred suspension of
adenosine-5'-carboxylic acid (14.0 g., 0.05 mole) in re-distilled
.beta.-chloroethanol (150 ml.) at 10.degree.-15.degree. C. After
thirty minutes at this temperature, the mixture was stirred at the
room temperature for sixteen hours. At the end of this period,
ether was added to precipitate adenosine-5'-(.beta.-chloroethyl)
carboxylate as HCl salt. The crude hydrochloride salt of
adenosine-5'-(.beta.-chloroethyl) carboxylate was stirred with
aqueous NaHCO.sub.3, filtered, washed successively with water,
acetone and ether. The dried residue (11.0 g., 65%, m.p.
205.degree.-206.degree. C.) was recrystallized from acetone to give
the analytically pure ester with no substantial change in melting
point. [.alpha.].sub.D.sup.26 -35.+-.2.2.degree. C. (c, 0.96 in
1N.HCl).
Analysis Calcd. for C.sub.12 H.sub.14 ClN.sub.5 O.sub.5.1/2H O: C,
40.08; H, 4.25; Cl, 10.07; N, 20.00; O, 25.25 Found: C, 39.79; H,
4.42; Cl, 10.20; N, 20.78; O, 25.11
EXAMPLE 12
Adenosine-5'-(N-cyclobutyl) carboxamide (13)
Adenosine-5'-(.beta.-chloroethyl) carboxylate (3.0 g.) was added to
cyclobutylamine (10 ml.) in N.sub.2 atmosphere. After the
exothermic reaction was over, the mixture was refluxed for thirty
minutes, and then the solvent was evaporated under reduced
pressure. The oily residue was taken up in hot absolute ethanol,
filtered (norit) and the filtrate on cooling gave 2.5 g. (86%) of
the adenosine-5'-(N-cyclobutyl) carboxamide. Recrystallization from
absolute ethanol gave pure adenosine-5'-(N-cyclobutyl) carboxamide;
m.p. 234.degree.-235.degree..
Analysis Calcd. for C.sub.14 H.sub.18 N.sub.6 O.sub.4 : C, 50.32;
H, 5.42; N, 25.14 Found: C, 50.52; H, 5.56; N, 24.72
EXAMPLE 13
2',3'-O-(4-Chlorobenzylidene) adenosine-5'-(N-ethyl) carboxamide
monohydrochloride (21)
A mixture of adenosine-5'-(N-ethyl) carboxamide (2 g.; 0.0065 mole)
and p-chloro benzaldehyde dimethyl acetal (10 ml.) in dioxane (100
ml.) was gently refluxed using Barrett water separator trap. The
temperature in the reflux condenser was adjusted such that any
methanol formed would slowly distil off. After 21/4 hours, dry DMF
(10 ml.) was added to the reaction mixture, followed by another 10
ml. of DMF after 51/4 hours, while refluxing was continued. A
4N-HCl dioxane solution (4 ml.) was then added to the clear hot
reaction mixture and allowed to stand. After three days at the room
temperature, the waxy solid was filtered (1.3 g.; m.p.
153.degree.-157.degree. dec.). The filtrate, on adding ether, gave
some more product (0.43 g.). Recrystallization from ethanol gave
the pure 2',3'-O-(4-chlorobenzylidene) adenosine-5'-(N-ethyl)
carboxamide as a mono hydrochloride, melting at
163.degree.-166.degree. dec.; R.sub.f 0.73 (system: n-butanol
saturated with water).
Analysis Calcd. for C.sub.19 H.sub.20 Cl.sub.2 N.sub.6 O.sub.4 :
Cl, 15.17; N, 17.98; O, 13.70 Found: Cl, 14.93; N, 17.77; O,
13.78
Nmr spectra confirmed the structure of the compound.
* * * * *