Online article for Non-subscribers

Pay per view

Heterocycles has a pay-per-view service for Non-subscribers.
You will be able to directly purchase the full text article through PayPal.
Your purchased Paper can be downloaded after the payment is completed.
An e-mail will be sent the URL to download the paper.
If you have any questions, please contact:

Price: ¥ 4,400 (Yen only)
Period: This Article can be accessed for 7 days.

Paper | Regular issue | Vol 85, No. 6, 2012, pp.1405-1416
Published online, 19th April, 2012
DOI: 10.3987/COM-12-12463
Synthesis of 5,6-Disubstituted Thieno[2,3-d]pyrimidines from 4-Chloropyrimidines

Kazuhiro Kobayashi,* Teruhiko Suzuki, Taketoshi Kozuki, Naoki Matsumoto, Hidetaka Hiyoshi, and Kazuto Umezu

*Division of Applied Chemistry, Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, 4-101 Koyama-minami, Tottori 680-8552, Japan


Facile reaction sequences for the preparation of 5,6-disubstituted thieno[2,3-d]pyrimidines starting with 4-chloropyrimidines have been developed. 4-Chloro-6-methoxypyrimidines were aroylated at the 5-positions via lithiation with LDA and subsequent treatment with benzaldehyde or N-methoxy-N-methylbenzamides to give aryl(4-chloro-6-methoxypyrimidin-5-yl)methanones. These pyrimidinyl ketones were transformed in one-pot into 5,6-disubstituted 4-methoxythieno[2,3-d]pyrimidines by a successive treatment with sodium sulfide, BrCH2EWGs, and sodium hydride. Lithiation of 4,6-dichloro-2- (methylsulfanyl)pyrimidine at the 5-position was followed by treatment with tertiary formamides to give 4-chloro-6-(dialkylamino)pyrimidine-5-carboxaldehydes, which could be transformed into 5,6-disubstituted 4-(dialkylamino)thieno[2,3-d]pyrimidines via aryl[4-chloro-6-(dialkylamino)pyrimidin-5-yl]methanones using the same one-pot thiophene ring forming sequence.