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Synthesis of 4‐Aminopyrimidines from 1,2,4‐Oxadiazoles, V [1] . Reductive Formation of 2‐(Benzoylamino)indole from 3‐(2‐Aminobenzyl)‐5‐phenyl‐1,2,4‐oxadiazole and Its Transformation to 6‐Phenyl‐8 H ‐pyrimido‐[1,6‐ a : 4,5‐ b ']diindole, a New Heterocyclic Ring System
Author(s) -
Bata Imre,
Korbonits Dezső,
Kolonits Pál,
Podányi Benjamin,
TakácsyErős Tünde,
Simon Kálmáan
Publication year - 1993
Publication title -
chemische berichte
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 136
eISSN - 1099-0682
pISSN - 0009-2940
DOI - 10.1002/cber.19931260814
Subject(s) - chemistry , ring (chemistry) , indole test , catalysis , oxadiazole , medicinal chemistry , raney nickel , catalytic hydrogenation , stereochemistry , organic chemistry
Catalytic hydrogenation of 5‐substituted 3‐(2‐aminobenzyl)‐1,2,4‐oxadiazoles 7 give 2‐(acylamino)indoles 10 . Treatment of 2‐(benzoylamino)indoles 10a–c with acid leads to the novel 6‐phenyl‐8 H ‐pyrimido[1,6‐ a : 4,5‐ b ']diindoles 19a–c . A route for the new ring formation is proposed. Catalytic hydrogenation of 19a (Raney nickel, 70°C, atmospheric pressure) saturates the 6‐phenyl ring but leaves the pentacyclic ring system intact. The structure of 19a is confirmed by an X‐ray crystallographic analysis.