A Simple Procedure for the Side-Chain Substitution of 2-Alkyl-3<b>
<i>H</i>
</b>-quinazoline-4-thiones: Application in Synthesis
作者:Gamal A. El-Hiti
DOI:10.1055/s-2004-815923
日期:——
Double lithiation of 2-alkyl-3H-quinazoline-4-thiones at nitrogen and at the α-hydrogen of the 2-alkyl group (Me, Et, Pr) has been achieved with n-butyllithium at -78 °C in anhydrous THF under nitrogen. Reactions of the dilithium reagents obtained with various electrophiles (iodomethane, iodoethane, 1-bromobutane, D2O, benzaldehyde, 4-anisaldehyde, butan-2-one, cyclohexanone, benzophenone, phenyl isothiocyanate, tetraisopropylthiuram disulfide) gave the corresponding modified 2-substituted 3H-quinazoline-4-thiones 4-22 in excellent yields.
2- 烷基-3H-喹唑啉-4-硫醚在氮和 2-烷基(Me、Et、Pr)的δ-氢处与正丁基锂在-78 °C的无水四氢呋喃中在氮条件下实现了双重石化作用。将得到的二锂试剂与各种亲电体(碘甲烷、碘乙烷、1-溴丁烷、D2O、苯甲醛、4-甲氧基苯甲醛、丁-2-酮、环己酮、二苯甲酮、异硫氰酸苯酯、二硫化四异丙基秋兰姆)反应,可以得到相应的改性 2-取代 3H-喹唑啉-4-硫酮 4-22,收率极高。