An Efficient Synthesis of New Pyrazolines and Isoxazolines Bearing Thiazolyl and Etheral Pharmacophores
作者:Manisha R. Bhosle、Jyotirling R. Mali、Umesh R. Pratap、Ramrao A. Mane
DOI:10.5012/bkcs.2012.33.6.2012
日期:2012.6.20
A convenient synthetic route has been developed to synthesize 5-(4-((2-phenylthiazol-4-yl) methoxy)phenyl)-3-(4-sustituted phenyl)pyrazolines (5a-f) and 5-(4-((2-phenylthiazol-4-yl)methoxy)phenyl)-3-(4-substituted phenyl)isoxazolines (6a-f) starting from 2-phenyl-4-chloromethylthiazole (1). The chloromethylthiazole (1) was first condensed with 4-hydroxy benzaldehyde (2) for obtaining 4-((2-phenylthiazol-4-yl)methoxy)benzaldehyde (3). Claisen-Smidth condensation of 4-((2-phenylthiazol-4-yl)methoxy)benzaldehyde (3) and acetophenones has been carried in alkaline alcohol and obtained 3-(4-((2-phenylthiazol-4-yl)methoxy)phenyl)-1-(4-substituted phenyl)prop-2-en-1-ones (4a-f). The cyclocondensation of 2-propen-1-ones has been first time carried separately with hydrazine hydrate and hydroxylamine hydrochloride in aqueous micellar tetradecyltrimethylammonium bromide (TTAB) medium for getting the titled heterocycles with good to excellent yields.
以 2-苯基-4-氯甲基噻唑(1)为起点,开发出了一条简便的合成路线,用于合成 5-(4-((2-苯基噻唑-4-基)甲氧基)苯基)-3-(4-取代苯基)吡唑啉类化合物(5a-f)和 5-(4-((2-苯基噻唑-4-基)甲氧基)苯基)-3-(4-取代苯基)异恶唑类化合物(6a-f)。氯甲基噻唑(1)首先与 4-羟基苯甲醛(2)缩合,得到 4-((2-苯基噻唑-4-基)甲氧基)苯甲醛(3)。4-((2- 苯基噻唑-4-基)甲氧基)苯甲醛 (3) 与苯乙酮在碱性醇中进行 Claisen-Smidth 缩合,得到 3-(4-((2-苯基噻唑-4-基)甲氧基)苯基)-1-(4-取代苯基)丙-2-烯-1-酮 (4a-f)。在胶束十四烷基三甲基溴化铵(TTAB)水介质中,2-丙烯-1-酮首次分别与水合肼和盐酸羟胺进行了环缩合反应,从而以良好至极佳的收率得到了标题杂环。