U.S. patent application number 10/004829 was filed with the patent office on 2002-07-04 for process for preparing 2-chloro-5-chloromethylthiazole.
Invention is credited to Inoue, Yoshihisa, Miyazaki, Takashi, Satou, Makoto.
Application Number | 20020087008 10/004829 |
Document ID | / |
Family ID | 18865322 |
Filed Date | 2002-07-04 |
United States Patent
Application |
20020087008 |
Kind Code |
A1 |
Miyazaki, Takashi ; et
al. |
July 4, 2002 |
PROCESS FOR PREPARING 2-CHLORO-5-CHLOROMETHYLTHIAZOLE
Abstract
A novel process for preparing 2-chloro-5-chloromethylthiazole is
provided which is suitable for industrial application. The process
for preparing 2-chloro-5-chloromethylthiazole involves allowing
2-halogenoallyl isothiocyanate to react with chlorinating agent in
the presence of an aromatic hydrocarbon which may have one or more
substituents.
Inventors: |
Miyazaki, Takashi;
(Hikari-shi, JP) ; Satou, Makoto; (Hikari-shi,
JP) ; Inoue, Yoshihisa; (Hikari-shi, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
18865322 |
Appl. No.: |
10/004829 |
Filed: |
December 7, 2001 |
Current U.S.
Class: |
548/202 |
Current CPC
Class: |
C07D 277/32
20130101 |
Class at
Publication: |
548/202 |
International
Class: |
C07D 277/62 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 28, 2000 |
JP |
400802/2000 |
Claims
What is claimed is:
1. A process for preparing 2-chloro-5-chloromethylthiazole of the
following formula (I): 7by allowing 2-halogeno-allyl isothiocyanate
of the following formula (II): 8(wherein Hal respresents chlorine
or bromine) to react with chlorinating agent in the presence of an
aromatic hydrocarbon which may have one or more substituents.
2. The process according to claim 1 wherein the aromatic
hydrocarbon which may have one or more substituents is toluene,
chlorobenzene or dichlorobenzene.
3. The process according to claim 1 wherein the aromatic
hydrocarbon which may have one or more substituents is toluene.
4. The process according to claim 1 wherein Hal in the formula (II)
is chlorine.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a novel process for
preparing 2-chloro-5-chloromethylthiazole.
[0003] 2. Description of the Prior Art
[0004] 2-chloro-5-chloromethylthiazole is an important compound as
an intermediate product in a process for preparing biologically
active compounds such as insecticides (see, for example, Japanese
Patent Application Laid-Open No. 3-157308 (1991)). It can be
prepared by, for example, the following processes.
[0005] Japanese Patent Application Laid-Open No.63-83079 (1988)
discloses a process for preparing 2-chloro-5-chloromethylthiazole
by allowing allyl isothiocyanate to react with chlorinating agent
as described in the following scheme (A): 1
[0006] This process requires a large amount of chlorinating agent
and the reaction has to be performed under a high temperature,
which produces many by-products. Therefore, it is not so suitable
for industrial application.
[0007] Alternatively, Japanese Patent Application Laid-Open No.
4-234864 discloses a process for preparing
2-chloro-5-chloromethylthiazole by allowing allyl isothiocyanate
derivative to react with chlorinating agent as described in the
following scheme (B): 2
[0008] This process is suitable for industrial application which
can be performed using approximately an equal amount of
chlorinating agent under moderate condition to give a high yield.
However, inert solvent (diluent) such as halocarbon may preferably
be used to give a high yield, which requires high production
cost.
[0009] Japanese Patent Application Laid-Open No. 2000-247963 (2000)
discloses a process which involves allowing 2-halogenoallyl
isothiocyanate to react with chlorinating agent in a dipolar
aprotic solvent such as acetonitrile. This process, however, has a
disadvantage that the solvent cannot be reused since it is
difficult to separate and collect the solvent such as acetonitrile
from water.
[0010] Accordingly, a novel process for preparing
2-chloro-5-chloromethylt- hiazole suitable for industrial
application is still needed in which an excess amount of
chlorinating agent is not required, moderate conditions can be used
to give a high yield, and solvent can be collected easily.
[0011] The object of the present invention to provide a novel
process for preparing 2-chloro-5-chloromethylthiazole which is
suitable for industrial application.
SUMMARY OF THE INVENTION
[0012] Aromatic hydrocarbons and derivatives thereof (particularly
toluene) are reactive with chlorinating agent. The present
inventors unexpectedly found, as a result of intense studies, that
2-chloro-5-chloromethylthiazole can be obtained at a high yield by
allowing 2-halogeno-allyl isothiocyanate to react with chlorinating
agent in the presence of aromatic hydrocarbons which may have one
or more substituents, and accomplished the present invention based
on the findings.
[0013] In other words, the present invention provides:
[0014] (1) a process for preparing 2-chloro-5-chloromethylthiazole
of the following formula (I): 3
[0015] by allowing 2-halogeno-allyl isothiocyanate of the following
formula (II): 4
[0016] (wherein Hal represents chlorine or bromine) to react with
chlorinating agent in the presence of an aromatic hydrocarbons
which may have one or more substituents;
[0017] (2) the process according to (1) above wherein the aromatic
hydrocarbons which may have one or more substituents is toluene,
chlorobenzene or dichlorobenzene; and
[0018] (3) the process according to (1) above wherein the aromatic
hydrocarbons which may have one or more substituents is
toluene.
[0019] (4) the process according to (1) above wherein Hal in the
formula (II) is chlorine.
DETAILED DESCRIPTION OF THE INVENTION
[0020] A 2-halogenoallyl isothiocyanate of the following formula
(II): 5
[0021] (wherein Hal represents chlorine or bromine) is a known
compound which can be prepared by any known processes. One
unlimiting example of such process involves heating a mixture of
2,3-dihalogeno-1-propene (e.g., 2,3-dichloro-1-propene) with
thiocyanate represented by M(SCN)n (wherein M represents metal or
ammonium group, and n indicates the valence of M) in the presence
of water (see, Japanese Patent Application Laid-Open No. 9-136874
(1997)).
[0022] The process according to the present invention may be
performed in the presence of an "aromatic hydrocarbons which may
have one or more substituents". The aromatic hydrocarbon in the
"aromatic hydrocarbon which may have one or more substituents"
herein may include, for example, benzene, naphthalene and
phenanthrene. The "aromatic hydrocarbon" may be substituted with,
for example, C.sub.1-4 alkyl group (e.g., methyl, ethyl, propyl,
isopropyl, butyl, isobutyl, s-butyl or t-butyl) and/or halogen
(e.g., fluorine, chlorine, bromine or iodine) and number of
substituents is preferably 1 to 3. Examples of such "aromatic
hydrocarbons which may have one or more substituents" are toluene,
o-, m-, p-xylene and xylene isomeric mixtures, ethylbenzene,
cumene, cymene, mesitylene, chlorobenzene, as well as o-, m- or
p-dichlorobenzene and isomeric mixtures of dichlorobenzene.
Preferable examples of "aromatic hydrocarbons which may have one or
more substituents" are chlorobenzene, dichlorobenzene (o-, m- or
p-dichlorobenzene or mixtures thereof) and toluene, among them
toluene is particularly preferable. The "aromatic hydrocarbons
which may have one or more substituents" may be used alone or in
combination of two or more thereof.
[0023] Preferably 0.1 to 20 parts and more preferably 0.5 to 5
parts by weight of the "aromatic hydrocarbons which may have one or
more substituents" may be used relative to 1 part by weight of the
above-described 2-halogenoallyl isothiocyanate.
[0024] The term "chlorinating agent" herein refers to chlorine or a
compound which releases chlorine under reaction conditions, such as
sulfuryl chloride or phosgene. The chlorinating agent is typically
used in an amount of 0.8 to 2 equivalents, preferably 1.0 to 1.5
equivalents, and more preferably 1.05 to 1.30 equivalents relative
to the above-described 2-halogenoallyl isothiocyanate.
[0025] For example, a reaction process according to the present
invention using 2-chloroallyl isothiocyanate as the starting
material and sulfuryl chloride as the chlorinating agent can be
particularly described with reference to the following scheme.
6
[0026] The process according to the present invention can be
performed, for example, under the following conditions.
[0027] The reaction may typically be performed at -60 to 60.degree.
C., preferably at -10 to 50.degree. C. and more preferably at 10 to
40.degree. C. though a wide range of temperature may be
selected.
[0028] The reaction may preferably be performed under atmospheric
pressure though reduced, atmospheric or pressurized pressure may be
used.
[0029] The reaction may typically be performed for from 10 minutes
to 50 hours and preferably for 1 to 20 hours.
[0030] After reaction completed, 2-chloro-5-chloromethylthiazole
can be isolated by any known methods. For example, reaction mixture
may be washed with a suitable amount of water, oil layer may be
separated and collected, and then the "aromatic hydrocarbons which
may have one or more substituents" may be removed by, for example,
vacuum distillation. The "aromatic hydrocarbons which may have one
or more substituents" may be collected for recycling.
[0031] Hereinafter, the present invention will be described in more
detail with reference to the following examples though they are not
intended to limit the scope of the present invention.
EXAMPLE 1
[0032] 2-chloroallyl isothiocyanate (75 g) was mixed with
chlorobenzene (136 mL), heated to 30.degree. C. and added dropwise
with sulfuryl chloride (84 g) for 3 hours. After stirring at
30.degree. C. for 2 hours, the reaction mixture was added to water
(94 g). Separated chlorobenzene layer was added with water (18 g)
followed by aqueous solution of 38% potassium carbonate (48 g), and
stirred for 30 minutes. Thereafter, oil layer was separated from
aqueous layer. The oil layer was distilled under reduced pressure
to collect chlorobenzene. The residue was further distilled under
reduced pressure to give 77g of 2-chloro-5-chloromethylth- iazole
(purity=80%, yield=75%)
EXAMPLE 2
[0033] 2-chloroallyl isothiocyanate (86 g) was mixed with
chlorobenzene (136 mL), heated to 30.degree. C. and added dropwise
with sulfuryl chloride (83 g) for 3 hours. After stirring at room
temperature for 15 hours, the reaction mixture was added to water
(94 g). Additionally, chlorobenzene (40 mL) was added to the
mixture which was then heated to 40.degree. C. and stirred for 1
hour. Thereafter, separated chlorobenzene layer was added with
water (18 g) followed by dropwise aqueous solution of 38% potassium
carbonate (75 g) and stirred for 30 minutes, and oil phase was then
separated from aqueous layer. The oil layer was enriched under
reduced pressure to collect chlorobenzene. The enriched residue was
further distilled under reduced pressure to give 75 g of
2-chloro-5-chloromethylthiazole (purity=95%, yield=76%)
EXAMPLE 3
[0034] 2-chloroallyl isothiocyanate (30 g) was mixed with toluene
(40 mL), and added dropwise with sulfuryl chloride (45 g) at room
temperature for 1 hour. After stirring at room temperature for 2
hours, deposited crystal was collected by filtration, washed with
toluene (40 mL), mixed with water (40 mL), heated to 40.degree. C.
and then cooled to room temperature, and added with aqueous
solution of 38% potassium carbonate (16 g) to adjust pH to
approximately 2. Then, oil layer was separated from aqueous layer.
The oil layer was distilled under reduced pressure to give 26.0 g
of 2-chloro-5-chloromethylthiazole (purity=95%, yield=73%)
EXAMPLE 4
[0035] 2-chloroallyl isothiocyanate (30 g) was mixed with toluene
(40 mL), and added dropwise with sulfuryl chloride (45 g) at room
temperature for 1 hour. After stirring at room temperature for 2
hours, the mixture was heated to 40.degree. C., stirred for 1 hour,
and then added dropwise with water (5 mL). Then, aqueous solution
of 38% potassium carbonate (16 g) was added at room temperature to
adjust pH to approximately 2. Then, water (10 mL) was added and
separated. Toluene layer was enriched under reduced pressure to
collect toluene (80%) and then the enriched residue was further
distilled under reduced pressure to give 27.1 g of
2-chloro-5-chloromethylthiazole (purity=98.0%, yield=79%)
EXAMPLE 5
[0036] 2-chloroallyl isothiocyanate (purity=95.5%, 94.2 kg) was
mixed with chlorobenzene (181.8 kg), heated to 30.degree. C. and
added dropwise with sulfuryl chloride (101.3 kg) for 4 hours. After
stirring at 30.degree. C. overnight, the reaction mixture was added
to water (113.6 kg). Separated chlorobenzene layer was added with
water (22.2 kg) followed by aqueous solution of 38% potassium
carbonate (39.1 kg), stirred for 1 hour, and allowed to stand
overnight. Thereafter, organic layer was separated from aqueous
layer. The organic layer was distilled under reduced pressure to
collect chlorobenzene. The residue was further distilled under
reduced pressure (102-104.degree. C./16-14 mmHg) to give 87.4 kg of
2-chloro-5-chloromethylthiazole (purity=97.4%, yield=75.2%).
EXAMPLE 6
[0037] 2-chloroallyl isothiocyanate (purity=94.3%, 1740 kg) was
mixed with toluene (1958 kg), heated to 30.degree. C. and added
dropwise with sulfuryl chloride (1892 kg) for 4 hours. After
stirring at 40.degree. C. for 2 hours, the mixture was added with
water (1538 kg) followed by aqueous solution of 38% potassium
carbonate (2393 kg), and stirred for 30 minutes, and oil layer was
then separated from aqueous layer. The oil layer was enriched under
reduced pressure to collect toluene. The enriched residue was
further distilled under reduced pressure (86-90.degree. C./4-2
mmHg) to give 1692 kg of 2-chloro-5-chloromethylthi- azole
(purity=95.0%, yield=77.9%).
[0038] As described above, a novel process for preparing
2-chloro-5-chloromethylthiazole is provided according to the
present invention in which an excess amount of chlorinating agent
is not required, moderate conditions can be used to give a high
yield, and solvent can be collected easily after reaction
completed.
* * * * *