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Synthesis of novel pyrido[3′,2′:4,5]thieno[3,2‐ d ]pyrimidines, pyrido[3″,2″:4′,5′]thieno[3′,2′:4,5]pyrimido[l,6‐ a ]benzimidazoles and related fused systems
Author(s) -
Bakhite E. A.,
AlSehemi A. G.,
Yamada Y.
Publication year - 2005
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.5570420606
Subject(s) - chemistry , synthon , chloroacetyl chloride , pyrimidine , carboxylate , aryl , pyridine , stereochemistry , medicinal chemistry , chloride , organic chemistry , alkyl
3‐Amino‐4‐aryl‐5‐ethoxycarbonyl‐6‐methylthieno[2,3‐ b ]pyridine‐2‐carboxamides 3a‐c were prepared from ethyl 4‐aryl‐3‐cyano‐6‐methyl‐2‐thioxo‐1,2‐dihydropyridine‐5‐carbonylates 1a‐c and reacted with some carbonyl compounds to give tetrahydropyridothienopyrimidine derivatives 6a‐c, 7a‐c and 8a‐c , respectively. Treatment of compound 3c with chloroacetyl chloride led to the formation of a next key compound, ethyl 2‐chloromethyl‐4‐oxo‐3,4‐dihydropyrido[3′,2′:4,5]thieno[3,2‐ d ]pyrimidine‐8‐carboxylate 9 . Also, 3‐amino‐2‐benzimidazolylthieno[2,3‐ b ]pyridine‐5‐carboxylate 5 and 2‐(3′‐aminothieno [2,3‐ b ]pyridin‐2′‐yl)‐4‐oxo‐3,4‐dihydropyrido[3′,2′:4,5]thieno[3,2‐ d ]pyrimidine‐8‐carboxylate 17 were prepared from 1c. The compounds 5, 9 and 17 were used as good synthons for other pyridothienopyrimidines and pyridothienopyrimidobenzimidazoles as well as for related fused polyheterocyclic systems.