6 7 8 hexahydroisoquinoline hydrochloride prepared according to o schnider et al helv chim acta 33 1437 1950 in toluene then during 15 minutes 164 4 g 1 610 mol of acetic anhydride and thereupon during 15 minutes 203 6 g 2 012 mol of triethylamine the ice bath was subsequently removed and the yellow solution was stirred at 20 u00b0 c for 20 hours the reaction mixture was cooled to 2 u00b0 c and extracted in succession with the following cold solutions once with 200 ml and twice with 100 ml of 2n sodium hydroxide solution once with 0 5 l and twice with 0 3 l of 2n hydrochloric acid each aqueous extract was back washed twice with the same 0 3 l aliquots of toluene the combined toluene solutions were dried over magnesium sulfate and evaporated at 40 u00b0 c 20 mbar and there were obtained 234 1 g 97 6 of a red brown oil according to thin layer chromatography this consisted of a mixture of e 2 acetyl 1 2 3 4 5 6 7 8 octahydro 1 p methoxybenzylidene isoquinoline z 2 acetyl 1 2 3 4 5 6 7 8 octahyro 1 p methoxybenzylidene isoquinoline and 2 acetyl 1 p methoxybenzyl 2 3 4 6 7 8 hexahydroisoquinoline in the ratio 40 45 15 in order to remove any polar impurities which may still have been present the crude material.