CS265317B1 - S-Allyl esters of N-acylmonothio-carbamic acids and their preparation - Google Patents

Abstract

The solution concerns the preparation of new substances S-allyl esters of N-acylmonothiocarbamic acids of the general formula I, where R means methyl, 2-chlorophenyl, styryl, 2-naphthyl or 3-chloro-2-benzo/b/thienyl. The essence of the solution lies in the fact that the acyl isothiocyanate of the general formula II, where R means the same as in the formula I, is treated with allyl alcohol in slightly polar organic solvents, preferably in benzene at a temperature of 18 to 23 °C, further heating to the boiling point of the reaction mixture results in a rearrangement of the transiently formed O-allyl esters of N-acylmonothiocarbamic acids of the general formula III, where R means the same as in the formula I. formulas I and II to S-allyl esters of N-acylmonothiocarbamic acids of general formula I. r-c-nh-c-s-ch2-ch=ch2 O II R-C-N=C=S O S 11 II R-C-NH-C-O-CH2-CH=C

Description

The invention relates to S-allyl esters of N-acylmonothiocarbamic acids of general formula I,

II

RC-NH-C“S“CH^CH=CH ₂ (I) where R means methyl, 2-chlorophenyl, styryl, 2-naphthyl or 3-chloro-2-benzo/b/thienyl and a method for their preparation. The above substances have not been described in the literature so far. The essence of the method for the preparation of substances according to the invention lies in the fact that on an acyl isothiocyanate of the general formula li jj

R-C-N=C-S (II) where R means the same as in formula I, is reacted in slightly polar organic solvents, preferably in benzene, at a temperature of 18 to 23 °C with allyl alcohol, whereby further heating to the boiling point of the reaction mixture results in a rearrangement of the transiently formed O-allyl esters of N-acylmonothiocarbamic acids of general formula III

About

SE II

RC-NH-CO-CH ₂ -CH=CH ₂ (III) where R means the same as in formulas I and II, to S-allyl esters of -N-acylmonothiocarbamic acids of general formula I.

The above-mentioned O-allyl esters of formula III can be isolated from the reaction mixture and rearranged to compounds of formula I can be carried out separately by heating in benzene, ethanol, acetone, etc.

The advantage of the method of preparation of the substances according to the invention is the easy availability of starting materials, simple washing procedure, as well as the fact that the products are obtained in good yields and purity. The importance of these substances lies in the fact that they can be used in reactions with nucleophilic reagents for the synthesis of compounds with the radical R-CO-NH-CO-, which can otherwise be prepared only from difficult-to-access acyl isocyanates. The compounds according to the invention also provide the possibility of preparing nitrogen heterocycles by cyclocondensation reactions.

The following examples illustrate, but do not limit, the subject matter of the invention.

Example 1

Preparation of N-(2-chlorobenzoyl)monothiocarbanoic acid S-allyl ester

To a solution of 2.96 g (15 mmol) of 2-chlorobenzoylisothiocyanate in 50 ml of benzene was added 1.82 g (2.5 ml; 18 mmol) of allyl alcohol and allowed to stand at room temperature for 4 days. The reaction mixture was then refluxed for 10 h, the benzene was evaporated and the residue was crystallized from carbon tetrachloride to give 3 g (80%) of the product.

Example 2

Preparation of O-allyl ester of N-/3-phenylpropenoyl/monothiocarbamic acid

To a solution of 5.86 g (30 mmol) of 3-phenylpropenoylisothiocyanate in 20 ml of benzene was added 3.64 g (5 ml, 36 mmol) of allyl alcohol and allowed to stand at room temperature for 4 days. The reaction mixture was poured into 250 ml of n-hexane, the precipitated product was filtered off with suction, dried and crystallized from a methanol-water mixture. Yield 5.33 g (73%) _from mp 103-105 °C. For (243.7) calculated: 63.14% C; 5.30% H; 5.66% N; found: 63.28% C; 5.12% H; 5.70% N.

Example 3

Preparation of N-(3-phenylpropenoyl)monothiocarbamic acid S-allyl ester

A. To a solution of 11.36 g (60 mmol) of 3-phenylpropenoyl isothiocyanate in 40 ml of benzene was added 6.57 g (9.03 ml? 65 mmol) of allyl alcohol and allowed to stand at room temperature for 4 days. The resulting solution was refluxed for 11 h _; the solvent was evaporated and the residue, after crystallization from carbon tetrachloride, gave 11.56 g (80%) of the product.

B. A solution of 2.56 g (10 mmol) of N-(3-phenylpropenoyl)monothiocarbamic acid O-allyl ester in 20 ml of ethanol is refluxed for 11 h. The ethanol is evaporated and the residue, after crystallization from carbon tetrachloride, gives 2.05 g (80%) of the product.

C. In the same manner as in the previous case, 2.10 g (81%) of product is obtained by refluxing in acetone for 60 hours.

Example 4

Preparation of N-(2-naphthoyl)monothiocarbamic acid S-allyl ester

To a solution of 4.27 g (20 mmol) of 2-naphthoylisothiocyanate in 15 ml of toluene was added 2.33 g (3.20 ml? 23 mmol) of allyl alcohol and allowed to stand at room temperature for 4 days. Further, in the same manner as in Example 1, 4.35 g (80%) of the product was obtained.

The physicochemical properties and elemental analyses of the substances according to the invention are given in Table 1.

Table 1

acids ob . formula I Compound Extract Formula M. t. (°C) Calculated/found ^( _C0 - -NH-CO) ³ R (%) (M _r ) SC SH %N Methyl 50 C _fi H _q N0 ₉ S 86 to 89 45.27 5.70 8.80 1 682 (159.2) (CCl^-petroleum ether) 45.43 5.56 8.99 1 714 2-chlorophenyl 83 C, ,Η^ΟΙΝΟ,Ξ 66 to 68 51.67 3.94 5.48 1 657 (255.7) (CC1 ₄ ) 51.49 3.82 5.61 1 690 Styryl 80 ^{C13H13NO2S ​ ​ ​} 140 to 144 63.14 5.30 5.66 1 700 (247.3) (CC1 ₄ ) 63.31 5.17 5.59 1 735 2—naphthyl 80 ^{C15H13NO2S ​ ​ ​} 142 to 145 66.41 4.83 5.16 1 653 (271.3) (CC1 ₄ ) 66.32 4.90 5.03 1 687 3-chloro-2-benzo- 98 ^{C13H10C1NO2S2 ​ ​ ​} 98 to 100 50.08 3.23 4.49 1 658 /b/thienyl (311.8) (methanol-water) 50.21 3.12 4.61 1 682

^a Values in cm measured in CHCl^

Claims (2)

1. S-allyl esters of N-acylmonothiocarbamic acids of the formula (I) wherein R is methyl, 2-chlorophenyl, styryl, 2-naphthyl or 3- chloro-2-benzo [b] thienyl. 2. A method of preparing ob. of formula (I) according to claim 1, characterized in that the acyl isothiocyanates of formula (II), (0) R-C-N-C = S (II) wherein R is the same as in ob. Formula I is employed in low polar organic solvents preferred in benzene at 18 to 23 ° C by allyl alcohol and transient O-allyl esters of N-acylmonothiocarbamic acids of general formula III 0 S II II RC-NH-CO-CH 2 -CH = CH 2 (III) where R is the same as in formulas (I) and (II) and is further heated to the temperature of the reaction mixture to produce N-acylmonothiocarbamic acid S-alkyl esters of formula I. Severografia, np, MOST Price $ 2.40