坦索罗辛EP杂质B

反应条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

实验步骤: Intermediate XI (10.5 g) is boiled in 5% HCl (250 ml) under a reflux condenser for 16 to 18 h. The course of the reaction is controlled with TLC detecting the starting substance. After the reaction is complete, the reaction mixture is concentrated to about ⅓ of its volume, then, a saturated solution of sodium carbonate (50 ml) is slowly added dropwise under stirring. After the addition, pH˜10 is controlled and the reaction mixture is stirred for 0.5 hour, then let to crystallize at 0° C. The precipitated crystals are sucked off and the filtrate is concentrated to ½ of its volume and let to crystallize at 0° C. Both fractions (4 g+8 g) of white to brownish crystals are combined and re-crystallized from water. The yield is 7.52 g (80%). the reaction mixture is concentrated to about ⅓ of its volume a saturated solution of sodium carbonate (50 ml) is slowly added dropwise After the addition, pH˜10 the reaction mixture is stirred for 0.5 hour to crystallize at 0° C the filtrate is concentrated to crystallize at 0° C re-crystallized from water