Ethanethiol → Hydrochloric Acid

Participants

Reaction Steps

To a stirred solution of 0.46 ml ethanethiol in 40 ml dry tetrahydrofuran (THF) under nitrogen at -10° is added dropwise 2.3 ml n-butyllithium (2.28M in hexane). This solution is added to a solution of 1.91 g (±)-[4R*,4aS*,10bR*]-7-bromo-4-(methylsulfonyloxymethyl)-1,3,4,4a,5,10b-hexahydro-9-methoxy-2-methyl-2H-[1]benzopyrano[4,3-c]pyridine in 25 ml THF. After stirring 2 h at 25°, 5 ml H2O is added and the reaction mixture concentrated under reduced pressure. The residue is partitioned between 25 ml H2O and 50 ml CH2Cl2. The CH2Cl2 phase is washed with 20 ml H2O, dried over Na2SO4, filtered and concentrated. Flash chromatography with CH2Cl2 /MeOH (40:1) yields an oil which is dissolved in 40 ml isopropyl alcohol. The solution is warmed at 50° and 1 ml 3.4N HCl/ethyl acetate is added. After cooling overnight the product is filtered, washed with isopropyl alcohol/ether (1:1) and dried to afford the title compound, m.p. 268°-269° dec (HCl salt).

Provenance & Evidence