Studies on Pyrimidine Derivatives and Related Compounds. XLIV. Syntheses of Thiazolo [3, 2-a] pyrimidine Derivatives
作者:Akira Takamizawa、Kentaro Hirai、Teruyuki Ishiba、Yoshihiro Matsumoto
DOI:10.1248/cpb.15.731
日期:——
Ethyl 2-thio-1, 2, 3, 4-tetrahydropyrimidine-5-carboxylate (VIII) and 2-thio-1, 2, 3, 4-tetrahydropyrimidine-5-carbonitrile (XXIII) were used for various kinds of condensation reactions. From the reaction with ethylene dibromide, VIII gave biscompound IX, and with phenacyl-bromide and p-chlorophenacylbromide thiazolo [3, 2-a] pyrimidine derivatives were obtained. In this reaction, 5H-thiazolo [3, 2-a] pyrimidine derivative (XIII, XVII, XXV) and the 7H-isomer (XIV, XVIII, XXVI) were obtained separately. The structures of these isomers were assigned from NMR and UV spectra. In this thiazolo [3, 2-a] pyrimidine syntheses, 3-hydroxy compounds (XII, XVI, XXIV) were considered to be the key intermediates.
2-thio-1, 2, 3, 4-四氢嘧啶-5-甲酸乙酯(VIII)和 2-thio-1, 2, 3, 4-四氢嘧啶-5-甲腈(XXIII)被用于各种缩合反应。VIII 与二溴化乙烷反应得到双化合物 IX,与苯酰溴和对氯苯酰溴反应得到噻唑并[3, 2-a]嘧啶衍生物。在这一反应中,分别得到了 5H-噻唑并[3, 2-a]嘧啶衍生物(XIII、XVII、XXV)和 7H-异构体(XIV、XVIII、XXVI)。这些异构体的结构是通过核磁共振和紫外光谱确定的。在噻唑并[3, 2-a]嘧啶的合成过程中,3-羟基化合物(XII、XVI、XXIV)被认为是关键的中间体。