addition rate 0 1 ml min the reaction progression was monitored by tlc upon reaction completion the reaction mixture was charged to a 24 ammonium chloride solution 20 ml slowly at a temperature of 25 u00b0 c the reaction mixture was mixed and settled organic layer was separated and aqueous layer was extracted with ethyl acetate 3 u00d7 20 ml the combined organic layers were filtered over a bed of sodium sulfate and the filtrate was concentrated by distillation to dryness 1 57 g crude solids were isolated 95 yield and carried to the next step 1h nmr 400 mhz chloroform d 1 u03b4 ppm 3 88 4 01 m 4h 1 85 1 96 m 2h 1 08 1 64 m 7h lcms u2212 ms 310 and 292 rf 0 074 by tlc hexane etoac 1 1 step b 18 ml of 0 005n hydrochloric acid solution 0 02 equiv was charged to the distillation residue from step a the reaction mixture was mixed at 70 u00b0 c for 3 hours and monitored by tlc upon reaction completion the reaction mixture was cooled to 25 u00b0 c and charged to another suitable reactor containing 22 ml of a 5 sodium chloride solution the reaction mixture was mixed until all salt dissolved followed by extraction with ethyl acetate 8 u00d7 200 ml the combined organic layers were filtered over a bed of sodium sulfate and the filtrate was concentrated by.