US3839416A - Trimethyl ester of carboxydithioimido-carbonic acid - Google Patents

Abstract

1. THE COMPOUND

CH3-S-C(-S-CH3)=N-COO-CH3

Description

United States Patent Int. Cl. C07c 149/20 U.S. Cl. 260-481 C 1 Claim ABSTRACT OF THE DISCLOSURE Compounds of the formula:

RS (H) RiS where R, R and R are as defined hereinafter are useful as chemical intermediates. When reacted with o-phenylenediamines, they form Z-benzimidazolecarbamic acid alkyl esters, which compounds are useful as fungicides.

Exemplary of the compounds is methyl bis(methylthio) methyleneaminoformate.

CROSS REFERENCE TO RELATED APPLICATIONS This application is a divisional of my copending application Ser. No. 681,102, filed Nov. 7, 1967, now US. Pat. 3,562,290.

BACKGROUND OF THE INVENTION BRIEF SUMMARY OF THE INVENTION This invention relates to novel compounds of the following formula:

O=NC 0 R2 Ins wherein R and R can be the same or different and are alkyl of 1 through 4 carbon atoms, alkenyl of 3 through 5 carbon atoms, cyclohexyl,

@ or Qua;

provided that R and R can be joined to form a ring containing 2 or 3 methylene units;

X is, halo gen, methyl or nitro;

n is 0, 1 or 2, provided that when n is 1 or 2, the substituents do not have to be identical;

R is methyl, ethyl, isopropyl or sec-butyl.

Patented Oct. 1, 1974 NR2 solvent NHz where R, R and R are as previously described; and where Z is alkyl of 1 through 5 carbon atoms, halogen, nitro or hydrogen.

DETAILED DESCRIPTION OF THE INVENTION The novel alkyl bis(alkyl or arylthio)methyleneaminoformates of the invention can be prepared by a two-step sequence as indicated in the following equations:

Reaction 1 /C=NHH(ha1ogen) I R15 Reaction 2 RS RS Optionally, the first step can be conducted in the manner illustrated by the following equation:

Optional Reaction 1 where n is 2 or 3.

The reaction of mercaptans with thiocyanates or cyanogen halides as set forth in Reaction 1 is known in the art and is explained in greater detail in J. Org. Chem. 29, page 739 (1964). The teachings of this reference are incorporated herein by reference.

The novel alkyl bis(alkyl or arylthio)methyleneaminoformates of the invention are produced as illustrated in Reaction 2, when the product of Reaction 1 is reacted with a chloroformate in the presence of an acid acceptor.

The acid acceptor can be an organic or inorganic base such as sodium hydroxide, sodium bicarbonate, or triethylamine in a polar or non-polar solvent such as ether, benzene, dimethylformamide, acetone, cyclohexane, dioxane or water.

The conditions of Reaction 2 are not critical. Generally, the reaction will be conducted with agitation at room temperature under atmospheric pressure. The time of the reaction also is not critical. The reaction will be continued until the desired alkyl bis(alkyl or ary1thio)methylaminoformate has formed; generally this will take from 30 minutes to 5 hours.

After the reaction has been completed, the compounds can be isolated by conventional methods.

As previously set forth, the novel compounds of the invention can be used for the synthesis of Z-benzimidazolecarbamate acid, alkyl esters by reacting them with phenylenediamines in the presence of a suitable solvent at temperatures from 25 to 150 C.

The reaction can also be run in the absence of a solvent; however, the use of polar or non-polar solvents such as tetrahydrofuran, water-acetic acid, ethanol or dimethylformamide is preferred.

The concentrations of the starting materials in the reaction mixture are only limited by the handling characteristics of the reaction mass.

During the course of the reaction, the reaction mixture should be stirred while the temperature is maintained between 25 to 150 C. The time of this reaction can range from 30 to 300 minutes. When the reaction is complete, the 2-benzimidazolecarbamate acid, alkyl ester product will be precipitated by cooling. The product is then isolated by conventional techniques such as filtration.

The invention will be more easily understood and practiced by reference to the following illustrative examples. All parts are parts by weight unless otherwise indicated.

EXAMPLE 1 Synthesis of Methyl bis(methylthio)methyleneaminoformate Seventeen parts of solid sodium bicarbonate is added to a suspension of 15.7 parts of dimethyl dithioiminocarbonate hydrochloride in cold C.) acetone (200 parts) which contains 9.5 parts of methyl chloroformate. The mixture is stirred for 30 minutes at 5 C., then for four hours at room temperature.

The precipitate present is filtered and the filtrate is dried over magnesium sulfate. Removal of the solvent gives 77 parts of methyl bis(methylthio)methyleneaminoformate. This product is sufiiciently pure for reaction with o-phenylenediamine to form 2-benzimidazolecarbamic acid, ester.

A pure sample of the product is obtained by recrystallization from chloroform-ether solvent, and it melts at 48 50 C. and gives the following analysis: calculated for C5H9NO2S2.

Calculated: C, 33.45; H, 5.12; N, 7.88. Found: C, 33.50; H, 5.02; N, 7.82.

EXAMPLE 2 Synthesis of 2-Benzimidazolecarbamic Acid, Methyl Ester Methyl bis(methylthio)methyleneaminoformate (17.9 parts) is added to a solution of parts of o-phenylenediamine in 200 parts of tetrahydrofuran. The mixture is refluxed for 3 hours, cooled and the precipitate present is filtered. The identity of the isolated 2-benzimidazolecarbamic acid, methyl ester is established by comparison of the melting point and infrared spectrum with those of an authentic sample.

EXAMPLE 3 One-Step Synthesis of 2-Benzimidazolecarbamic Acid, Methyl Ester A solution of 10% sodium hydroxide is added drop wise to a cold (512 C.) stirred solution of 39.4 parts of dimethyl dithioiminocarbonate hydrochloride and 25 parts of methyl chloroformate in 100 parts of water.

When the pH of the medium reaches 7.5, the addition of sodium hydroxide is stopped and a slurry of o-phenylenediamine (21.6 parts) in 10 parts of glacial acid is added. The reaction mixture is stirred and refluxed for 75 minutes, cooled and the solid present is filtered. The solid is washed with a small amount of alcohol to give 13 parts of the subject compound. The identity of the product is confirmed by infrared spectral comparisons.

EXAMPLES 4-13 The following intermediates are prepared in the manner of methyl bis(methylthio)methyleneaminoformate of Example 1 by substituting equivalent amounts for the dimethyl dithioiminocarbonate hydrochloride and methyl chloroformate used in Example 1.

Starting materials Product 4, Butyl methyl dithloiminosec-B uty1[(butylthi0) (in ethylcarbonate hydrochloride plus thio)methyleneamino] sec-butyl chloroformate. formate. 5. Allyl cyclohexyl dithioimino- Isopropyl[(allylthio) (cycloearbonate hydrochloride plus hexylthio)methyleneamino]- iso propyl chloroformate.

6 3,4-dichlorobenzyl methyl dithioiminocarbonate hydrochloride plus methyl chloroform ate. Methyl[(3,4-dichlorbenzylthio) (methylthio)methyleneaminoh'ormate.

Ethyl[(methylthio) (phenylthio)methyleneamino]- formate. Ethyl[(trimethylene dithio) methyleneaminohormate.

Methyl bis(butylthio)methyleneimlnoiormate.

Isopropyl[(methylthio) (4- nitrophenylthio)methyleneamino1forrnate.

Methyl bis(phenylthio)methyleneaminoiormate.

Methyl[(allylthio) (4chlorophenylthio)methyleneaminohormate.

Ethyl[(2-ehloro-4-tolylthio) (methylthio)rnethyleneamino1lormate.

EXAMPLES 14-16 Heating o-phenylenediamine and an alkyl 'bis(alkyl or arylthio)methyleneaminoformate in a polar or a nonpolar solvent gives 2-benzimidazolecarbamic acid, alkyl esters as in Examples 2 and 3. The following examples are illustrative of this process:

Starting materials Product 14- sec-B utyl [(butylthio)-(metl1ylthio) methyleneamino] formate plus o-phenylenediaminc.

15..--.- Isopropyl [(allythio)-(eyclohexylthio)methyleneamino] formate plus o-phenylenediaminc. 16. Ethyl [(methylthio) (phenyl- 'o) methyleneamino]- lormate plus o-phenylenediaminc.

Z-benzirm'dazolecarbamic acid,

sec-butyl ester.

2-benzimidazolecarbamic acid, isopropyl ester.

Z-benzimidazoleearbamlc acid, ethyl ester.

EXAMPLES 17-25 The following 2-benzimidazolecarbamic iacid, alkyl esters can be prepared from the reactants given below according to the methods described in Examples 2 and 3.

Reactants Product 17. 4-butyl-l,Z-phenylenediamine 6-butyl-2-henzimidazoleand methyl bis(methylthio)- carbamic acid, methylester. methylcneaminolormate.

18- 4-mcthyl-l,Z-phenylenediamine E-methyI-Z-benmmidazoleand methyl bis(methylthio) carbamic acid, methyl ester. methyleneaminolormate.

19- 4-chloro-1,Z-phenylenediamine 5-ehlor0-2-benzimidazolcand methyl bis(methylthio)- carbamic acid, methyl ester. methyleneaminoiormate.

20 4-br0mo-l,2-phenylenediamine fi-bromo-Z-benzimidazoleand methyl bis(methylthio)- oarbamic acid, methyl ester. methyleneaminoformate.

21. 4-nitr0-1,2-phenylenediamine E-nitro-Z-benzrmidazoleand methyl bis(methylthio)- oarbamic acid, methyl ester. methyleneaminoformate. I

22- 4-Iluoro-1,Z-phcnylenediarnine 5-flu0ro-2-benz1m1dazo1eand methyl bis(methylthio)- carbamic acid, methyl ester. methyleneaminoformate.

23- 4-iodo-l,Z-phenylenediamine 5-iodo-2-benzimidazoleand methyl bis(methylthio) carbamic acid, methyl ester. methyleneaminoformate.

24- 3-chloro l,Z-phenylenediamine 4-ehl0ro-2-benz 1m1daz0lcand sec-butyl bis(methylearbamic acid, sec-butyl thio)-methyleneamiuoester. formate.

25- 3-brom0-l,Z-phenylenediamine 4-bromo-2-benzimidazoleand ethyl bis(methylthio)- carbamic acid, ethyl ester. methyleueaminoformate.

I claim: 5 FOREIGN6 PATENTS The compound 1,135,583 4/1968 England.

L OTHER REFERENCES 5 Chemical Abstracts, vol. 59 (1964), p. 8554 old. 0333 Burger: Medicinal Chem, p. 75, RS403B8.

References Cited Timmons et al.: J. Org. Chem. 32, 1566 (1967).

UNITED STATES PATENTS LORRAINE A. WEINBERGER, Primary Examiner 2,651,658 9/1953 B l 260-471 10 J. F. TERAPANE, Assistant Examiner 3,755,363 8/1973 Timmons et a1. 260-327 M 3,652,256 3/1972 DAmico 71-90

Claims (1)

1. THE COMPOUND