DD203319A1 - PROCESS FOR THE PREPARATION OF THIADIAZOLINES - Google Patents

Abstract

The aim of the invention is to develop a process for the preparation of 5-alkyl- or -arylamino-delta & exp4! -1,3,4-thiadiazolin-2-ylidene-cyanoacetic acid alkyl esters or cyanoacetamides. D. thiadiazolines d. general formula III, in d. R is an alkoxy radical or an amino group u. R & exp1! represent an alkyl-o.Arylrest, can by reaction d. Dithietane d. general formula I, in d. R. d. has the above meaning, with Thiosemicarbazidderivaten d. general formula II, in d. R & exp1! as defined above. D. thiadiazolines d. general formula III can be used as organic intermediates for further syntheses. They are particularly suitable for the preparation of other heterocycles.

Description

Process for the preparation of biadiazolines Field of application of the invention

The invention relates to a process for the preparation of 5-alkyl or -arylamino-A ^ -I ^ Vthiadiazolin-2-ylidene-cyanoacetic acid alkyl esters or cyanoacetami- »den. These thiadiazolines can be used as organic intermediates for further syntheses. They are particularly suitable for the preparation of other heterocycles.

Characteristic of the known technical solutions

5-Alkyl- or -arylamino-Δ ^ -ΐ, 3,4-thiadiazolin-2-ylidene-cyanoacetic acid alkyl ester or cyanoacetamides are not yet known.

Object of the invention

The aim of the invention is to develop a process for the preparation of these thiadiazolines.

Explanation of the essence of the invention

The thiadiazolines of the general formula III, are provided in which E represents an alkoxy group or an amino group and E is an alkyl or aryl may be prepared by reacting the Dithietane of the general formula I wherein K * has \ AEIE above meaning, with 03aiosemicarbazidder ^v ivaten of general formula II wherein R * ^{1 is} as defined above

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is to be produced.

The reactions are carried out in organic solvents, preferably in alkdol-chloroform mixtures or methylformamide. It is expedient to react the components of general formula I and II in a molar ratio of 1: 2. The reaction temperatures lie in the Hegel at the boiling temperatures of the solvents or solvent mixtures used. The reaction ^times range from a few minutes up to 5 ^hours ·

The isolation of the biiadiazolines III occurs in some cases by cooling the reaction mixtures. The thiazolidines crystallize out, which can be recrystallized from organic solvents for further purification. On the other hand, the thiadiazolines are concentrated by evaporation of the reaction mixtures i.Vak. and to work through the residue with water. Further purification of the products can be carried out by recrystallization from organic solvents »

Embodiments Example 1

5-ethylamino-Δ ^ -1,3,4-thiadiazoline-2-ylidene-cyanoacetate methylester

0.005 mol of 1,3-dithietane-2,4-dlylidene-bis (cyanoacetic acid methyl ester) and 0.01 mol of 4-ethyl-thiosemicarbazide are refluxed in a mixture of 10 ml of methanol and 10 ml of chloroform for 4 hours. It is allowed to cool to 15 ⁰ O, filtered off, washed the precipitate successively with methanol and a little chloroform and crystallized from dioxane to.

Yield: 58% of theory Melting point: 233-235 ° C

(226,3) Ber. 0 42.46 H 4.46 N 24.76 Gef. C 42.1? H, 4.61 -H 24.38 ¹ H-HMR (DMSO-D ₆ ): NGH ₂ CH ₃ 1.13 »NCH ₂ CH ₃ 3.19, OCH ₃ 3.73 ppm.

-3- / Λ Υ \ M η Zi

Embodiment 2;

Metbylamino-Δ-1,3,4-thiadiazolin-2-ylidene-cyanoacetamide

0.05 mol of 1,3-dithietane-2,4-diylidene-bis (cyanoacetamide) and 0.01 mol ^ -Methyl thiosemicarbazid are heated in 15 ml of dimethylformamide while shaking until complete dissolution · The reaction mixture is concentrated i.Vak , A, the remaining residue is triturated with water, filtered off, washed with ethanol and the precipitate is recrystallized from ethanol.

Yield: 33% d.Th, Melting point: from 225 ⁰ C Z.

(197.2) Ber. 36.54 H 3.58 N 35.51 Gef. C 36.21 H 3.80 N 35.35

Table: Further illustrated thiadiazolines III

E E Composition Analysis: Ber./Gef. F

(Molecular weight) C E N

CH ₃ 'CrH ₈ N ₄ O ₂ S 39.61 3.80 26.40 22

(212,2) 39,71 4,02 25,92 23

OCH ₃ C ₃ H ₇ CgH ₁₂ N ₄ O ₂ S 44.99 5.05 23.32 22

(240,3) 45,00 5,21 23,26 23

OCH ₃ C ₄ H ₉ ν C ₁₀ H ₁₄ N ₄ O ₂ S 47.23 5.55 22.03 22

(254.3) 47.41 5.02 22.38 23

OCH ₃ CH ₂ -GH = CH ₂ C ₉ H ₁₀ N ₄ O ₂ S 45.36 4.23 23.52 22

(238,3) 44,92 4,11 23,21 22

C ₆ H ₅ ° 12 ^H 10 ^N 4 ° 2 ^{S 52 '54 3} » ^{67 20i04 2e}

(274.3) 52.41 3.52 19.75 26

CH ₃ C ₈ H ₁₀ N ₄ O ₂ S 42.46 4.46 24.76 24

" ^v (226,3) 42,50 4,80 24,40 24

C ₉ H ₁₂ N ₄ O ₂ S 44.99 5.03 23.32 24

(240,3) 45,21 5,30 23,62 24

C ₁₀ H ₁₄ N ₄ O ₂ S 47.23 5.55 22.03 2;

(254.3) 47.40 5.92 21.82 2;

OC ₂ H ₅ C ₄ H ₉ C ₁₁ H ₁₆ N ₄ O ₂ S 49.23 6.01 20,88 2;

(268,3) 49,25 6,20 20,68

CH ₂ -CH = CH ₂ C ₁₀ H ₁₂ N ₄ O ₂ S 47.60 4.79 22.21 2 \

(252.3) 47.41 4.40 21.93

C ₁₃ H ₁₂ N ₄ O ₂ S 54.15 4.20 19.43 2 \

, "'~' (288,3) 54,12 4,33 19,58 2 '

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ROC S _x .CN

C = O 0 = O + 2 R ¹ NH-O-NHNH

NO S ^X COR S

II

H) C ^ ,, Β

= 0 "C-NHR ¹

III

Claims (1)

invention claim Process for the preparation of thiadiazolines of the general formula III in which B is an alkoxy radical / I or an amino group and B is an alkyl or aryl radical, characterized in that dithietane of the general formula I ₁ in which H has the above meaning, with ühiosemicarbazidderiva ^ en the general formula II in which B is as defined above.