Synthesis and reactions of 2,3-dihydrothiazolo[3,2-a]pyrimidine derivatives.
作者:TOSHIO KINOSHITA、YASUJI UESHIMA、KOUJI SAITOH、YASUFUMI YOSHIDA、SUNAO FURUKAWA
DOI:10.1248/cpb.35.90
日期:——
The reaction of 2-amino-2-thiazoline (1) with acetylene carboxylates (2) afforded 5-substituted 2, 3-dihydro-7H-thiazolo [3, 2-a] pyrimidin-7-ones (3). 7-Bromomethyl-2, 3-dihydro-5H-thiazolo [3, 2-a] pyrimidin-5-one (10) was obtained by the reaction of 1 with γ-bromoacetoacetyl bromide. Treatment of 10 with N-bromosuccinimide provided the 6-bromo compound (12). The 7-bromomethyl compounds (10 and 12) were converted to 7-morpholinomethyl derivatives by treatment with morpholine. When 3a (unsubstituted-), 3b (5-ethoxycarbonyl-), and 3c (5-hydroxymethyl-) were treated with 5% hydrochloric acid, covalent hydration occurred across the 5, 6-carbon-carbon bond, giving 5-hydroxy-2, 3, 5, 6-tetrahydro-7H-thiazolo [3, 2-a] pyrimidin-7-one derivatives (16a, 16b, and 16c). On the other hand, in the case of 11 (7-methyl-) and 17 (5-phenyl-), the dihydrothiazole ring was cleaved to give 3 (and 1) - (2-mercaptoethyl) -6-methyl (and phenyl) -2, 4 (1H, 3H) -pyrimidinedione (19 and 18).
2-氨基-2-噻唑啉(1)与乙炔羧酸酯(2)反应得到5-取代的2,3-二氢-7H-噻唑并[3,2-a]嘧啶-7-酮(3)。 1与γ-溴乙酰乙酰溴反应得到7-溴甲基-2,3-二氢-5H-噻唑并[3,2-a]嘧啶-5-酮(10)。用N-溴代琥珀酰亚胺处理10得到6-溴化合物(12)。通过吗啉处理,7-溴甲基化合物(10和12)转化为7-吗啉代甲基衍生物。当3a(未取代的-)、3b(5-乙氧基羰基-)和3c(5-羟甲基-)用5%盐酸处理时,在5、6-碳-碳键上发生共价水合,得到5-羟基- 2,3,5,6-四氢-7H-噻唑并[3,2-a]嘧啶-7-酮衍生物(16a、16b和16c)。另一方面,在11(7-甲基-)和17(5-苯基-)的情况下,二氢噻唑环断裂,得到3(和1)-(2-巯基乙基)-6-甲基(和苯基) )-2, 4(1H, 3H)-嘧啶二酮(19 和 18)。