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[1]Benzothienopyrimidines. II. Study of the electrophilic substitutions of [1]benzothieno[3,2‐ d ]pyrimidine and [1]benzothieno[3,2‐ d ]pyrimidin‐4‐(3 H )one
Author(s) -
Rault Sylvain,
De Sévricourt Michel Cug,
Touzot Paulette,
Robba Max,
ElKashef Hussein
Publication year - 1980
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.5570170710
Subject(s) - nitration , chemistry , pyrimidine , halogenation , derivative (finance) , nitro , electrophile , medicinal chemistry , stereochemistry , organic chemistry , catalysis , alkyl , financial economics , economics
The nitration and bromination of both [1]benzothieno[3,2‐ d ]pyrimidin‐4(3 H )one ( 1 ) and [1]benzothieno‐[3,2‐ d ]pyrimidine ( 2 ) has been studied. Nitration of 1 at −30° afforded a mixture of 8‐nitro[1]benzothieno‐[3,2‐ d ]pyrimidin‐4(3 H )one ( 7b ) (70%) and 6‐nitro[1]benzothieno[3,2‐ d ]pyrimidin‐4(3 H )one ( 7a ) (30%). However when the nitration was carried out at 60°, the 6,8‐dinitro derivative 8 was the result. On the contrary, the nitration of 2 at −30° gave a single nitration product, 8‐nitro[1]benzothieno[3,2‐ d ]pyrimidine ( 11 ). The bromination of both 1 and 2 gave the corresponding 8‐bromo derivatives 10 and 13 . Assignment of structure of all the products was based on ir and nmr spectral studies and on unequivocal syntheses.