Reactions of Substituted Carbohydrazides with Electron-poor Olefins

Abstract

Substituted carbohydrazides 1a -e reacted with ethenetetracarbonitrile (2) in dimethylformamide with formation of diacylhydrazines 4a -e and 5-amino-1-substiuted pyrazole-3,3,4-tricarbonitriles 5a -e. On the other hand, 1a-c reacted with diethyl (E)-2,3-dicyanobutenedioate (3) to give oxadiazinone and pyrazolone derivatives 12a -e and 13a -e, respectively.

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

“…A different type of heterocyclization was reported in the reactions of carbohydrazides 67 derived from benzoic acid and some hetarylcarboxylic acids with E - 1a [ 65 – 66 ]. In these cases, the formation of mixtures of two products is described, and in both cases pyrazol-3-ones 68 were obtained in ca.…”

Chemistry and heterocyclization of carbohydrazides

“…To a stirred solution of ethenetetracarbonitrile (TCNE) ( 26 ) in dimethylformamide (DMF), carbohydrazides 1 was added to give diaroylhydrazines 30 and 1,1,2,2‐tetracyanoethane (TCNE‐H 2 ) 28 [38]. Formation of these products may be rationalized via the following steps [38]. …”

“…Reaction of substituted carbohydrazides 1 with 26 in DMF afforded 5‐amino‐1(substituted)‐1 H ‐pyrazole‐3,3,4(2 H )‐tricarbonitriles 79 [38]. …”

“…Mixing equimolar amount of carbohydrazides 1 with diethyl( E ) 2,3‐dicyanobutenedioate 80 in ethyl acetate under reflux led to the formation of pyrazole derivatives 83 [38]. …”

“…Solutions of diethyl ( E ) 2,3‐dicyanobutenedioate 80 and 1 were refluxed for 4–18 h in ethyl acetate to give 1,3,4‐oxadiazinone 223 , via elimination of one molecule of ethanol follwed by HCN [38]. …”