DD294943A5 - METHOD FOR PRODUCING CONDENSED N-HETEROCYCLES - Google Patents

Abstract

The invention relates to a process for the preparation of condensed N-heterocycles. The aim of the invention is to develop a process for the production of *. The condensed N-heterocycles can be used as organic intermediates for further syntheses. They are particularly suitable for displaying potentially biologically active compounds. According to the invention, the condensed N-heterocycles of general formula II wherein R is an alkyl radical and X is a carbalkoxy, optionally substituted carboxylic acid amide or cyano group can be prepared by reacting the general formula I wherein R and X are the above Have meaning, be prepared with cyanacetic hydrazide. Formulas {* * Cyanacetic hydrazide}

Description

Characteristic of the Prior Art 2-Alkylthio-5-amino-e, 7-dihydro-7-oxo-pyrazolo [1,5-a] pyrimidine-3-carboxylic acid derivative 6 are not yet known.

Object of the invention The aim of the invention is the development of a process for the preparation of new pharmaceutical active ingredients. Explanation of the essence of the invention

The object of the invention is ea, on the basis of cyanacetic hydrazide, a synthesis of 2-alkylthio-5-amlno-6,7-dihydro-7-oxopyrazolo [1,5-a] pyrimidine-3-carboxylic acid derivatives to allow.

According to the invention, the condensed N-heterocycles of the general formula II in which R is an alkyl radical and X is a carbalkoxy, optionally substituted carboxamide or a cyano group, by reacting the ketene-S, S-acetals of the general formula I, in R and X have the above meaning, are prepared with cyanacetic hydrazide. The reactions are carried out in protic organic solvents, preferably in alcohols. The reaction temperatures are at the boiling points of the solvents used. Depending on these reaction temperatures, the reaction times are 2 to 16 hours. Upon cooling the reaction mixtures to room temperature, the reaction products crystallize out. They can be purified after filtration by recrystallization from organic solvents.

embodiments Exercise booklet 1 B-amino-ej-dihydro ^ -methylthio ^ -oxo-pyrazoloH.B-alpyrimidin-S-carboxylic acid methylester A mixture of 0.001 mol of cyanacetic hydrazide, 0.001 mol of 2-cyano-3,3-bis (methylthio) acrylic acid methyl ester and 15 ml Ethanol is refluxed for 7 hours. The reaction mixture is allowed to cool to 2O ⁰ C, filtered from the precipitate,

Wash it with ethanol and recrystallize it from ethanol.

Yield: 78% of theory M .: 187-19O ⁰ C Embodiment 2 N-furfuryl-S-amino-e ^ -dihydro ^ ^ -oxo-methylthio pyrazoloII.S-al-pyrimidine-S-carboxylic acid amide

0.001 mol of cyanacetic hydrazine and 0.001 mol of N-furfuryl-cyano-S, -bis-methylthiojacrylic acid amide are refluxed in 15 ml of ethanol for 16 hours. It works as described in Example 1.

Yield: 47% of theory M .: 163-165 ⁰ C Implementation Example 3 B-amino-ej-dihydro ^ -methylthio ^ -oxo-pyrazolod.S-alpyrimidin-S-carbonitrile

0.001 mol of cyanacetic hydrazide and 0.001 mol of 2-cyano-3,3-bis (methylthio) acrylonitrile are reacted for 8 hours, as described under

Embodiment 1 described. Yield: 72% of theory M .: 193-195 ⁰ C

SSSElLu *

• J-

RS RS

H ₂ NHN NCCH,

X *

H, N-

-RSH

SR

= 0

Il

Claims (2)

Proceed η for the preparation of condensed N-heterocyclone of general formula II, in de. R is an alkyl radical and X is a carbalkoxy, optionally substituted carboxamide or a cyano group, qekennzelchnet in that Keten-S, S-acetals of the general formula I in which R and X have the above meaning, be reacted with cyanacetic hydrazide , For this 1 page formulas Field of application of the invention The invention relates to a process for the preparation of 2-alkylthio-5-amino-6,7-dihydro-7-oxo-pyrazolo (1,5-a) pyrimidine-3- carboxylic acid derivatives. These condensed N-heterocycles can be used as organic intermediates for further syntheses. you are particularly suitable for displaying potentially biologically active compounds.