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Syntheses of various 5‐(3′‐substituted phenyl)uracils
Author(s) -
Wellmar Ulf,
Hömfeldt AnnaBritta,
Gronowitz Salo
Publication year - 1996
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.5570330232
Subject(s) - chemistry , combinatorial chemistry , organic chemistry , medicinal chemistry
The Suzuki Pd(0)‐catalysed coupling between arylboronic acids and aryl bromides or iodides in weakly alkaline medium has been used for the preparation of 5‐(3′‐chlorophenyl)‐, 5‐(3′‐iodophenyl)‐, 5‐(3′‐aminophenyl)‐, 5‐(3′‐azidophenyl)‐, 5‐(3′‐methylthiophenyl)‐ and 5‐(3′‐styryl)‐substituted 2,4‐di‐ t ‐butoxypyrimidines. In the coupling between 2,4 di‐ t ‐butoxy‐5‐pyrimidineboronic acid and the six different aryl halides that were used as coupling partners, only 1‐azido‐3‐bromobenzene did not give satisfactory yields, 18%. The other five aryl halides gave the desired 5‐(3′‐substituted phenyl)‐2,4‐di‐r‐butoxypyrimidines in 41–92% yield. Dealkylation of these five 5‐(3′‐substituted phenyl)‐2,4‐di‐ t ‐butoxypyrimidines in 2.5 M hydrochloric acid gave the corresponding 5‐(bromoaryl)uracils in almost quantitative yields. 5‐(3′‐Azidophenyl)uracil was prepared in 43% yield directly from 5‐(3′‐aminophenyl)‐2,4‐di‐r‐butoxypyrimidine.