Lithiation of 3-(Acylamino)-2-unsubstituted-, 3-(Acylamino)-2-ethyl-, and 3-(Acylamino)-2-propyl-4(3<i>H</i>)-quinazolinones: Convenient Syntheses of More Complex Quinazolinones<sup>1</sup>
作者:Keith Smith、Gamal A. El-Hiti、Mohamed F. Abdel-Megeed、Mohamed A. Abdo
DOI:10.1021/jo950988t
日期:1996.1.1
3-(acetylamino)-2-ethyl-4(3H)-quinazolinones and 3-(pivaloylamino)- and 3-(acetylamino)-2-propyl-4(3H)-quinazolinones are lithiated at the benzylic position with LDA. The lithium reagents so produced also react with a variety of electrophiles to give the corresponding 2-substituted-4(3H)-quinazolinone derivatives in very good yields. However, lithiation of 3-(acylamino)-2-(1-methylethyl)-4(3H)-quinazolinones was unsuccessful
3-(新戊酰氨基)-和3-(乙酰氨基)-4(3H)-喹唑啉酮类与烷基锂试剂反应生成1,2-加成产物,收率很高。用LDA进行锂化并且在2位上具有区域选择性。由此获得的锂试剂与各种亲电试剂反应,以非常好的收率得到相应的取代衍生物。锂试剂与碘的反应产生氧化二聚的环状结构。3-(新戊酰氨基)-和3-(乙酰氨基)-2-乙基-4(3H)-喹唑啉酮和3-(新戊酰氨基)-和3-(乙酰氨基)-2-丙基-4(3H)-喹唑啉酮在LDA的苄基位置。如此产生的锂试剂还与多种亲电试剂反应,以非常好的收率得到相应的2-取代的-4(3H)-喹唑啉酮衍生物。然而,