作者:Eugene Babaev、Vadim Alifanov
DOI:10.1055/s-2006-958941
日期:2007.1
Stepwise conversion of pyrimidin-2(1H)-one to 2-amino-5-aryloxazoles via oxazolo[3,2-a]pyrimidinium salts is reported. The sequence involves, (i) regioselective N-alkylation of pyrimidone by phenacyl bromides, (ii) cyclization of obtained 1-(2-aryl-2-oxoethyl)pyrimidin-2(1H)-ones into oxazolo[3,2-a]pyrimidinium salts under the action of fuming sulfuric (or triflic) acid, and (iii) reaction of the obtained
有报道通过恶唑并[3,2-a]嘧啶盐逐步将嘧啶-2(1H)-one 转化为 2-氨基-5-芳基恶唑。该序列包括,(i) 苯甲酰溴对嘧啶酮进行区域选择性 N-烷基化,(ii) 将获得的 1-(2-aryl-2-oxoethyl)pyrimidin-2(1H)-ones 环化为 oxazolo[3,2-a ]嘧啶鎓盐在发烟硫酸(或三氟甲磺酸)的作用下,和(iii)得到的盐与肼反应生成2-氨基-5-芳基恶唑。