Studies on quinazolinones.<b>2</b>. Synthesis of 2-(4-benzylpiperazin-1-ylmethyl)-2,3-dihydro-5<i>H</i>-oxazolo[2,3-6]quinazolin-5-one and -2,3-dihydro-5<i>H</i>-thiazolo[2,3-<i>b</i>]quinazolin-5-one
作者:Chia-Yang Shiau、Ji-Wang Chern、Kang-Chien Liu、Chao-Han Chan、Mou-Hsiung Yen、Ming-Chu Cheng、Yu Wang
DOI:10.1002/jhet.5570270552
日期:1990.7
3-dihydro-5H-oxazolo[2,3-b]quinazolin-5-one (13). The title compound, 2-(4-benzylpiperazin-1-ylmethyl)-2,3-dihydro-5H-oxazolo[2,3-b]quinazolin-5-one (7) could be obtained by a reaction of either 12 or 13 with 1-benzylpiperazine respectively. Starting from the readily available 3-allyl-2H-thioxoquinazolin-4(3H)-one (16) via the analogous reactions gave the 2-bromomethyl-2,3-dihydro-5H-thiazolo[2,3-b]-quinazolin-5-one
为了在稠合的喹唑啉系列中寻找新的降压杂环,通过合适的反应序列合成了两种代表性的化合物。用异氰酸烯丙酯处理蒽腈,以定量收率得到2-(烯丙基脲基)苄腈(10)。将化合物10环化为3-烯丙基喹唑啉-2(1 H,4(3 H)-二酮(11)。四氯化碳中的11溴化反应将其转化为相应的3-(2,3-二溴丙基)衍生物(12)。产率92%,通过碱作用使12的环闭合,得到2-溴甲基-2,3-二氢-5 H-恶唑并[2,3 - b ]喹唑啉-5-酮(13)。标题化合物2-(4-苄基哌嗪-1-基甲基)-2,3-二氢-5 H-恶唑并[2,3 - b ]喹唑啉-5-酮(7)可通过以下任一种反应获得:12或13与1-苄基哌嗪分别使用。通过类似的反应,从容易获得的3-烯丙基-2 H-硫代喹唑啉-4(3 H)-one(16)开始,得到2-溴甲基-2,3-二氢-5 H-噻唑并[2,3- b ]-喹唑啉-5-酮(19),收率良好