2.6 g of (+/−)-cis-1,2-dimethoxy-4-(2-aminocyclohexyl)benzene are dissolved in 20 ml of methylene chloride and 1 ml of triethylamine. At RT, a solution of 2.4 g of 4-methoxycarbonylbenzoyl chloride in 30 ml of methylene chloride is added dropwise over a period of 3 h, and the mixture is stirred for 1 h and then extracted with 50 ml each of water, 2 N hydrochloric acid, sat. sodium bicarbonate solution and once more with water. The organic phase is dried with sodium sulfate, concentrated and crystallized from ethyl acetate. This gives 2.0 g (45.5% of Th.) of the title compound of m.p. 139-143° C.
