Solvent-free synthesis of quinazoline-2, 4 (1H, 3H)-diones using carbon dioxide and a catalytic amount of DBU

T Mizuno, M Mihara, T Nakai, T Iwai, T Ito

Index: Mizuno, Takumi; Mihara, Masatoshi; Nakai, Takeo; Iwai, Toshiyuki; Ito, Takatoshi Synthesis, 2007 , # 16 p. 2524 - 2528

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Citation Number: 34

Abstract

Abstract An ideal reaction system, which is aimed at sustainable chemistry, was developed. Under solvent-free conditions, quinazoline-2, 4 (1H, 3H)-diones were obtained in good to excellent yields from 2-aminobenzonitriles with only carbon dioxide (1 bar) and a catalytic amount of base (DBU or DBN). For example, 6, 7-dimethoxyquinazoline-2, 4 (1H, 3H)-dione, which is a key intermediate of several drugs (Prazosin, Bunazosin, and Doxazosin) was ...