反应详情

To the tetrahydrofuran solution under water cooling was added a solution of ethyl 3-ethoxycarbonyloxy-1,4-dihydro-1,4-dioxo-2-naphthoate, obtained by the procedure of Referential Example 22(1) using 3.41 g of ethyl 3-hydroxy-1,4-dihydro-1,4-dioxo-2-naphthoate, in 10 ml of tetrahydrofuran. The mixture was stirred at room temperature for 2 hours. The reaction solution was poured into 100 ml of ethanol, and the resulting crystals were collected by filtration and recrystallized from chloroform - ethanol to give the title compound, m.p. 224°-227° C., yield of 3.70 g.