DD233565A1 - METHOD FOR PRODUCING N HIGH 2-ALKYLIDENE-N HIGH 1-METHYL-CYANOTHIOFORMHYDRAZIDES - Google Patents

Abstract

The invention relates to a process for the preparation of N2-alkylidene-N1-methyl-cyanothioformhydraziden. The essence of the invention consists in the reaction of N1-methyl cyanothioformhydrazid with carbonyl compounds in the presence of acidic catalysts.

Description

Field of application of the invention

The invention relates to a process for the preparation of N ² -alkylidene-N ¹ -methyl-cyanothioformhydraziden by reaction of carbonyl compounds with IVP-methyl cyanothioformhydrazid. Such compounds are of interest as intermediates for the synthesis of potentially biologically active substances.

Characteristic of the known technical solutions

N ² -alkylidene-N ¹ -methyl-cyanylthioformhydrazides have not previously been disclosed.

Object of the invention

The aim of the invention is to find a simple process for the preparation of the title compounds from technically readily available starting materials.

Explanation of the essence of the invention.

The object is achieved in that N ¹ -methyl-cyanothioformhydrazid of the general formula I mit.Carbonylverbindungen of the general formula II, in which R ^{1 is} hydrogen and R ^{2 is} a phenyl group, optionally mono- or polysubstituted in various positions by alkyl, alkoxy , Nitro, hydroxy or halogen atoms, or R ¹ and R ^{2 may represent the} same or different, branched or unbranched alkyl groups or aralkyl groups. The reactions are carried out in C 1 -C ₄ -alcohols, in particular in ethanol, at elevated temperature up to the boiling point of the solvents used.

The reactions are acid-catalyzed and after addition of small amounts of concentrated sulfuric or hydrochloric acid or p-toluenesulfonic acid after a few minutes in almost quantitative yield, the title compounds of general formula III, in which R ¹ and R ^{2 have} the above significance. The precipitated yellow to orange colored reaction products are recrystallized from ethanol after filtration with suction and washing with water.

embodiments

The invention is explained in more detail by examples given below, without being limited thereto.

example 1

NM ^ Chlorbenzylidenl-NWiethyl-cyanothioformhydrazid

0.01 mol of N ¹ -methyl-cyanothioformhydrazid are heated with 0.01 mol of p-chlorobenzaldehyde in 50 ml of ethanol with the addition of 2 drops of concentrated sulfuric acid to boiling, cooled and filtered off with suction, washed with water and a little cold ethanol and recrystallized from ethanol.

Mp 187-189 ⁰ C. Yield: 95%

Example 2

N ² - [4-methylbenzylidene] -N ¹ -methyl-cyanothioformhydrazide

0.01 mol of N ^ methyl cyanothioformhydrazid are reacted with 0.01 mol of 4-methylbenzaldehyde in 50 ml of methanol as in Example 1 and worked up.

Mp: 159-160.5 ⁰ C Yield: 98%

Example 3

0.01 mol of N ¹ -methyl-cyanothioformhydr.azid are reacted with 0.01 mol of 4-methoxybenzaldehyde in 50 ml of ethanol as in Example 1 and worked up.

Mp 115-117 ⁰ C. Yield: 95%

CH;

NOON-

O = C '

NC-C-N-N = C

Claims (2)

-1- 721 10 Invention claim: 1. A process for the preparation of l ^ -alkylidene-IVP-methyl-cyanothioformhydrazides of the formula III, in which R ^{1 is} hydrogen and R ^{2 is} a phenyl group, which is also mono- or polysubstituted, in various positions by alkyl, alkoxy, nitro -, hydroxy groups or halogen atoms, or R ¹ and R ^{2 are the} same or different, branched or unbranched alkyl groups or aralkyl groups, characterized in that N ¹ -Methylcyanothioformhydrazid of formula I with carbonyl compounds of the formula II in which R ¹ and R ^{2 have} the above meaning in Ci-Gj alcohols at elevated temperature and addition of acidic catalysts are reacted. 2. The method according to item 1, characterized in that the reactions are carried out in ethanol with the addition of sulfuric acid as a catalyst. For this 1 page formulas