Potassium Hydroxide → 744162-52-5

Participants

Reaction Steps

A mixture of 253.9 g (0.935 mol) of (--)-1-(p-methoxybenzyl)-2-methyl-1,2,3,4,5,6,7,8-octahydroisoquinoline and 1.2 l. of diethylene glycol was warmed to 80°-100° and 260 g of potassium hydroxide (85 % A.C.S. grade) was added. The reaction mixture was heated to 210° and stirred at this temperature under a constant stream of nitrogen for 36 hours. During this period, time to time the stop cock was removed to allow escape of water vapor. If this is not done, the desired inner temperature of 210° cannot be attained. The dark brown solution was cooled to room temperature and diluted with water (600 ml) and extracted with ether (400 ml). The aqueous solution was made acidic with concentrated aqueous hydrochloric acid and then basified with concentrated aqueous ammonium hydroxide. The aqueous suspension was extracted with ethyl acetate (4×250 ml). The ethyl acetate solution was washed with water and dried. Removal of the solvent gave 172.5 g (72%) of crude (--)-1-(p-hydroxybenzyl)-2-methyl-1,2,3,4,5,6,7,8-octahydroisoquinoline. For analysis, a sample of this compound was recrystallized from tetrahydrofuran-heptane, mp 119°-120°, [α]25D-36.01° (c 0.98, MeOH).

Provenance & Evidence