反应详情

Following a procedure similar to that described in Example 1 above, 4.5 g of 2-(4-dimethylaminophenyl)carbonylbenzoic acid, 1.2 ml of thionyl chloride and 5.0 ml of methyl alcohol were interacted in 30.0 ml of ethylene dichloride in the presence of 1.3 ml of piperidine at ambient temperature for approximately ten minutes to obtain 4.0 g of 3-methoxy-3-(4-dimethylaminophenyl)phthalide (Formula II: R0 =R=R1 =R2 =R5 =H; R4 =R4' =R5 =Y=CH3 ; X=O), a pale peach-colored solid which melted at 112.5° to 114.5° C. A significant infrared maximum appeared at 1773 cm-1 (C=O;s). The nulcear magnetic resonance spectrum was consistent with the assigned structure. Analysis by mass spectrum showed m/e peaks at 283 (M+) and 252 (M+ -OCH3). A toluene solution of the product spotted on an acidic clay-coated paper developed a yellow-colored image.