Methanol → Methyl 1-amino-4-methoxy-4-(trifluoromethyl)cyclohexanecarboxylate

12.20 g (corresponds to about 37.58 mmol) of 1-amino-4-methoxy-4-(trifluoromethyl)cyclohexanecarboxylic acid (Example 18A) were suspended in 210 ml of methanol, and 10.4 ml (142.80 mmol) of thionyl chloride were added at 0° C. The mixture was boiled under reflux for 2 hours and cooled, another 10.4 ml (142.80 mmol) of thionyl chloride were added at 0° C. and the mixture was boiled under reflux for a further 2 hours. The reaction was cooled, another 10.4 ml (142.80 mmol) of thionyl chloride were added and the mixture was heated at reflux overnight until the reaction had gone to completion. For work-up, about 100 ml of methanol were distilled off and the concentrate was poured into 1 l of saturated aqueous sodium carbonate solution. The product was extracted with ethyl acetate and the organic phase was dried over sodium sulphate. Concentration by evaporation gave 7.01 g (73% of theory) of the title compound as a yellowish oil.