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N-SUBSTITUTED CYANACETOHYDRAZIDES IN THE SYNTHESIS OF 3,3-DIALKYL-1,2,3,4-TETRAHYDROISOQUINOLINES BY RITTER REACTION

Александр Георгиевич Михайловский, Денис Владимирович Корчагин, Алексей Владимирович Юсов, Оксана Владиславовна Гашкова
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Abstract


Cyanacetohydrazide, protected at the nitrogen atom of hydrazide group, underwent cyclocondensation by Ritter reaction with 3,3-dialkylbenzylcarbinols, forming 3,3-dialkyl-1,2,3,4-tetrahydroisoquinolines. The reagents used for the protection of hydrazide group were benzaldehyde, benzoyl chloride, phenyl isocyanate, and phenyl isothiocyanate. As a result, N-substituted derivatives of 2-(3,3-dialkyl-3,4-dihydroisoquinolin-1(2Н)-ylidene)acetohydrazide were obtained – N-phenylmethylidene ethanehydrazide, acetylbenzohydrazide, and N-phenylhydrazinecarboxamide. Cyanacetohydrazide that was acylated with phenyl isothiocyanate gave a heterocyclization product – 1,3,4-thiadiazole under these conditions.

 


Keywords


cyanacetohydrazide, 2-(3,3-dialkyl-3,4-dihydroisoquinolin-1(2Н)-ylidene)acetohydrazide, 1,3,4-thiadiazole, heterocycli-zation, Ritter cyclization.

Full Text: PDF (Russian) Supplementary File(s): scheme hydrazides (113KB) RSA_10b.cif (18KB) xray_10b (864KB) consent Hydrazides (851KB)


 

 

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