Abstract: In order to search for effective antimyocardial ischemic agents, fourteen new 3 4-(3-alkylamino-2-hydroxy)propoxy phenyl(benzyl)-substituted 4(3H)-quin zolinones (Ⅱ) were synthesized. Substituted o-aminobenzoic acids used as the starting materials were allowed to react with acetic anhydride and then p-aminophenol (method A), or with N- (4- hydroxyphenyl)formamide (method B), or with thionyl chloride and then N - (4 - hydroxybenzyl) formamide (methode C) to form 3-(4-hydroxyphenyl(benzyl)-substituted 4(3H)-quinazolinones (Ⅲ). The intermediate Ⅲ reacted with epichiorohydrin to form the epoxides (Ⅳ). The reaction of Ⅳ with an excess of isopropylamine or tert-butylamine in boiling chloroform gave the desired products. Of all the compounds synthesized, Compounds Ⅱ_3～5 and Ⅱ₁₃ were found to increase the tolerance of mice to hypoxia. Further evaluation is in progress.