反应详情

After adding 0.32 g of concentrated sulfuric acid and 3 g of platinum-on-charcoal catalyst (5%), a solution of 26.8 g of 5-(2-oxo-propoxy)-salicylamide and 17.6 g of α-(aminomethyl)-benzyl alcohol in 450 ml of methanol is hydrogenated under normal conditions until 1 mol equivalent of hydrogen has been taken up. The catalyst is filtered off, the solvent is evaporated and the crude α-[N-[2-(3-carbamoyl-4-hydroxy-phenoxy)-1-methyl-ethyl]aminomethyl]-benzyl alcohol thus obtained is dissolved hot in as little methanol as possible and the solution is cooled and seeded with crystals of the enantomer pair having the higher melting point. The crystals with a melting point of 160°-163° which are obtained after standing for several days yield, after a further crystallisation from methanol, one pur enantiomer pair with a melting point of 166°-168°. The enantiomer pair which has the lower melting point of 152°-154° is isolated from the first mother liquor after evaporating off the solvent, by fractional crystallisation using ethyl acetate or isopropanol.

1. filtrationThe catalyst is filtered off
2. customthe solvent is evaporated