of water and 50 ml of saturated brine the organic solution was evaporated at 70 u00b0 c yield 26 0 g 69 4 of theoretical yield of crude oxime 7 base z isomer the residue was dissolved at 80 u00b0 c in 250 ml of ethanol the solution was slowly cooled to 20 u00b0 c and stirred for 1 hour then cooled to u2212 15 u00b0 c and let stand for 12 hours the crystals were filtered off and washed with 2 u00d7 10 ml of ethanol yield 17 86 g 47 7 of theoretical yield of crystallized oxime 7 base z isomer purity 97 6 13 0 g of 4 2 4 difluorobenzoyl piperidine hydrochloride 14 83 g of e oxime 3 acetate and 2 6 g of potassium iodide are suspended in 52 ml of ethanol and 11 6 of 50 koh is added the suspension is stirred at 60 u00b0 c for 9 hours the reaction mixture ph 9 was evaporated to dryness the residue was dissolved in 200 ml of water ph was set up to 10 10 5 and the product was extracted with 3 u00d7 200 ml of chloroform collected organic layers are extracted with 50 ml of water 500 ml of 2 acetic acid and then 2 u00d7 250 ml of 2 acetic acid the water extract is alkalized with 50 naoh to ph 10 5 and the solution extracted with 3 u00d7 150 ml of chloroform chloroform solution is extracted with 2 u00d7 50 ml of water the solvent is evaporated at 60 u00b0.