Collect. Czech. Chem. Commun.
1984, 49, 1529-1535
https://doi.org/10.1135/cccc19841529
Synthesis and reactions of furocondensed systems containing indole skeleton
Anna Koreňová, Alžbeta Krutošíková, Miloslava Dandárová and Jaroslav Kováč
Department of Organic Chemistry, Slovak Institute of Technology, 817 37 Bratislava
Abstract
The new 1,2,4-triazolo[3''', 4''':6'', 1'']-1,2,4-triazino[4'', 5'':4,5]furo[3,2-b]indoles V and 1-acetyl-9H-pyrrolo[2',3':4,5]furo[3,2-b]indole (IX) were prepared from 1,9-dihydropyrrolo[2',3':4,5]furo[3,2-b]indole-2-carboxhydrazide I and 2-(2-nitrophenyl)-4H-furo[3,2-b]pyrrole-5-carboxylic acid, respectively. Compound I gave with triethyl orthoformate or with triethyl orthoacetate 1,2-dihydro-1,2,4-triazino[4'',5'':1',5']pyrrolo[2',3':4,5]furo[3,2-b]indol-1-one or its methyl analogue II. Substances II afforded with phosphorus pentasulfide thiones III reacting with hydrazine to furnish IV. Cyclization of the latter with triethylorthoformate or orthoacetate led to V. Compounds II and III can also be obtained by a deoxygenative cyclization of VI and VII with triethyl phosphite.
