Synthesis of spiro(indenepyrazole) and indenotriazinone derivatives from 4-substituted thiosemicarbazides and (1,3-dioxo-2,3-dihydro-1H-inden-2- ylidene)propanedinitrile

摘要

In a multistep reaction, N-substituted-5'-amino-4'-cyano-1,3-dioxo-1,3- dihydro-spiro[indene-2,3'-pyrazole]-2'(1H) carbothioamides (63-71 %) and 4-substituted-3-thioxo-3/y-indeno[1,2-e][1,2,4] triazin-9(4/H)-ones (17-26 %) have been formed, from a series of 4-substituted thiosemicarbazides 1a-f with (1,3-dioxo-2,3-dihydro-1H-inden- 2-ylidene)propanedinitrile 3 in aerated ethyl acetate. Rationales of these conversions involving the nucleophilic reactions and condensation are presented.