Indenoxadiazine, Indenopyrazole and Spiro Triazole Derivatives from (substituted ylidene)-N-phenylhydrazine Carbothioamides

Abstract

In a multistep reaction, indeno [2,1-e][1,3,4]oxadiazine-9-one, oxoindeno[1,2-c]-pyrazolecarbothioamide, (thioxo-1,2,4-triazaspiro[4.5]decadienylidene)malononitrile and spiro-(fluorine-9,3'-[1,2,4]triazoline)-5'-thione derivatives have been formed from a series of (substituted ylidene)-N-phenylhydrazinecarbothioamides 1a-e with (1,3-dioxo-2,3-dihydro-1H-inden-2-ylidene)propanedinitrile, 7,7',8,8'-tetracyanoquinodimethane and (2,4,7-trinitro-9H-fluoren-9-ylidene)propanedinitrile in aerated pyridine. Rationales of these conversions involving the nucleophilic reactions, condensation, dehydrogenation and oxidation are presented.

Recent Heterocyclic Compounds from (1,3‐Dioxo‐2,3‐dihydro‐1H‐inden‐2‐ylidene)propanedinitrile

“…Addition of a solution of 2‐substituted‐ N ‐phenylhydrazinecarbothioamides 49f , 49g , 49h , 49i , 49j in dry pyridine to a solution of 1 gave, upon chromatography of the residue, numerous zones. The 3‐cyano‐4‐oxo‐phenylindeno[1,2‐ c ]pyrazole‐1(4 H )‐carbothioamides 61 (Scheme ) was isolated .…”

“…Chromatographic evaluation of the product mixture resulting from the reaction of the 2‐substituted‐ N ‐phenylhydrazinecarbothioamides 49f , 49g , 49h , 49i , 49j with 1 in dry pyridine under gentle heating afforded numerous zones, from which 4a‐hydroxy‐3‐(substituted)‐indeno[2,1‐ e ]‐[1,3,4]‐oxadiazine‐9(4a H )‐ones 78a , 78b , 78c , 78d , 78e could be isolated (Scheme ) .…”

Synthesis of novel spiro(indolone‐3,2′‐[1,3,4]thiadiazol)‐2‐ones and evaluation of their antidepressant and anticonvulsant activities

“…A novel and a efficient procedure for the synthesis of thiosemicarbazones has been achieved via a multicomponents and catalyst‐free reaction of phenyl or p ‐ chlorophenyl isothiocyanate, hydrazine, and aldehydes or ketones [33]. Besides, thiosemicarbazones are versatile building blocks in the synthesis of densely substituted heterocycles [34–40]. It has been reported earlier that, isatin‐3‐thiosemicarbazones were cyclized to 5 H ‐ as ‐triazino[5,6‐ b ]indole‐3‐thiones in aqueous K 2 CO 3 [41–43].…”

A Facile Synthesis of Oxoindenothiazine and Dioxospiro(indene‐2,4′‐thiazine) Derivatives from (Substituted ethylidene)hydrazinecarbothioamides

“…Recently, the reactions of 2-substituted ylidene-N-phenylhydrazinecarbothioamides 2a-e with 1 afforded substituted indeno [2,1-e] [1,3,4]oxadiazinones 3a-e and 3-cyano-4-oxo-N-phenylindeno[1,2-c]pyrazole-1(4H)-carbothioamide (4) (Scheme 1) [12].…”

“…On the other hand, the synthesis of fused heterocycles and numerous impressive successes have been obtained from the reaction of 1 with thiosemicarbazides [7,[9][10][11][12], carbohydrazides [8], and diaryl acetamidines [13]. Because of variable bonding modes, biological implications, and structural diversity of thiosemicarbazones [14][15][16], they have been used as drugs and are reported to possess a wide variety of biological activities against bacteria, fungi, and certain types of tumor [17,18].…”