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Synthesis of pyrimidino[4,5‐ b ][1,5]benzodiazepin‐2‐ones and pyrimidino[1,6‐ a ]benzimidazol‐1‐ones from 4‐ethoxycarbonylamino‐1 H ‐1,5‐benzodiazpine‐3‐carbonitrile via 4‐(2‐aminoanilino)pyrimidin‐2(1 H )‐one‐5‐carbonitriles
Author(s) -
Takagi Kaname,
Aotsuka Tomoji,
Morita And Hikari,
Okamoto Yoshihisa
Publication year - 1986
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570230539
Subject(s) - chemistry , triethylamine , intramolecular force , primary (astronomy) , medicinal chemistry , ethanol , stereochemistry , organic chemistry , physics , astronomy
Abstract Reactions of 4‐ethoxycarbonylamino‐1 H ‐1,5‐benzodiazepine‐3‐carbonitrile (2) with aliphatic primary amines gave 1‐substituted 4‐(2‐aminoanilino)pyrimidin‐2(1 H )‐one‐5‐carbonitriles 3. Analogous reactions of 2 with aromatic primary amines afforded 2‐(2′‐anilino‐1′‐cyanovinyl)benzimidazoles 5 and 6. Upon treatment with triethylamine, 3 underwent intramolecular cyclization to give 3‐substituted 5‐aminopyrimidino[4,5‐ b ]‐[1,5]benzodiazepin‐2(3 H ,11 H )‐ones 8 . Heating of 3 with p ‐toluenesulfonic acid in ethanol gave 2‐substituted pyrimidino[1,6‐ a ]benzimidazol‐1(2 H )one‐4‐carbonitriles 9 . Reactions of 2 with hydrazines were also described. Mechanistic pathways are proposed to account for the products.