Nitropyrazoles 13.* Synthesis and reactivity of 1-methyl-3,5-dinitropyrazole-4-carbonitrile.Site of nucleophilic displacement of the nitro group in 4-R-1-methyl-3,5-dinitropyrazoles

摘要

A method for the synthesis of 1-methyl-3,5-dinitropyrazole-4-carbonitrile from 1,4-di-methyl-3,5-dinitropyrazole was developed.Nucleophilic substitution in 1,4-dimethyl-3,5-dinitropyrazole,1-methyl-3,5-dinitropyrazole-4-carboxamide,and 1-methyl-3,5-dinitro-pyrazole-4-carbonitrile involves solely the 5-NO2-group in the ring.1-Methyl-3,5-dinitro-pyrazole-4-carbonitrile reacts with thioglycolic acid phenylamide and potassium carbonate to give 4-amino-1-methyl-3-nitro-N-phenyl-1H-thieno[2,3-c]pyrazole-5-carboxamide.The use of glycolic acid phenylamide instead of thioglycolic acid N-phenylamide under analogous conditions resulted in 5-anilino-1-methyl-3-nitro-1H-pyrazole-4-carbonitrile.An explanation for the regiospeciflcity of the nucleophilic substitution of the 5-NO2 group in 4-R-1-methyl-3,5-dinitropyrazoles is given.