cis-3,3,5-trimethylcyclohexanol (cis-3,3,5-trimethylcyclohexanol) is used as a cyclomandelate drug intermediate in laboratory research and development and in chemical and pharmaceutical synthesis.
A method for the synthesis of cis-3,3,5-trimethylcyclohexanol (cis-3,3,5-trimethylcyclohexanal), a pharmaceutical intermediate of cyclobenzolate, was carried out according to the following steps:
A. To a reaction vessel was added 1,5,5-trimethylcyclohexen-3-one (2) 0.51 mol, 600 ml of a solution of 2-amino-5-chlorobenzoic acid with a mass fraction of 37%, the temperature of the solution was lowered to 0C, and the stirring speed was controlled at 110 rpm;
B, slowly add lithium powder 1.38mol, adding time control at 120min, after adding continue to react for 90min, and then slowly raise the temperature to 16 , the heating process control at 50min;
C, solution concentration under reduced pressure, the concentrate was added to 230ml of potassium bromide solution with a mass fraction of 28%, add 100ml of oxalic acid solution with a mass fraction of 38%, dimethylamine solution with a mass fraction of 57% was extracted for 7 times, the extracts were combined, washed sequentially with ethyl acetate solution with a mass fraction of 48%, butanone solution with a mass fraction of 60%, dewatered with calcium chloride dewatering agent. 1.7 kPa distillation under reduced pressure, the fraction at 80-86 C was collected and recrystallized in 88% mass fraction of cyclohexane solution to obtain crystalline cis-3,3,5-trimethylcyclohexanol (cis-3,3,5-trimethylcyclohexanal) 64.45 g, yield 89%.
