ChemInform Abstract: Chemistry and Heterocyclization of Thiosemicarbazones

Abstract

SHAWKY, A. M.; SHEHATTA, H. S.; J. Heterocycl. Chem. 49 (2012) 1, 21-37, http://dx.

Formation of Indazole Derivatives from 2,4-Disubstituted Thiosemicarbazides and some Chloro-p-Quinones

“…The radicals (7a-d) · being a precursor to 11. [8][9][10]17,[31][32][33] The latter reacts with the semiquinone Q-H˙ with elimination two molecules of HCl to give the indazole derivatives 8a-d or 10a-d via the intermediate 12.…”

Synthesis of Spiro(indenepyrazole) and Indenotriazinone Derivatives from 4-substituted Thiosemicarbazides and (1,3-dioxo-2,3-dihydro-1H-Inden-2-Ylidene)Propanedinitrile

“…[21][22][23] Recently we reported an efficient transformation of aldehyde thiosemicarbazides 4a-e with 3 into indeno[2,1-e] [1,3,4]oxadiazine-9-ones 5a-e and 4-oxoindeno [1,2-c] pyrazole-3-carbonitriles 6a-e (Scheme 1). 24 These intriguing transformations led us to investigate the reactions of 4-substituted thiosemicarbazides 1a-f with 3. The latter compound offer C/C multiple bonds and the electrophilic carbonyl and nitrile carbon atoms for attack by nucleophiles and compounds 1a-f may react at least with N 1 , N 2 and sulfur atoms as nucleophilic sites.…”