Hydrochloric Acid → Hydrochloric Acid

Participants

Reaction Conditions

Reaction Steps

(R)-2-(Toluene-4-sulfonyloxymethyl)-2,3,8,9-tetrahydro-7H-1,4-dioxino[2,3-e]indol-8-one (3.0 g, 8.0 mmole) and sodium azide (1.6 g, 24.0 mmole) were placed in 300 ml of DMF and the reaction mixture was heated at 45° C. for 15 hours. Most of the DMF was removed and the residue was partitioned between dichloromethane and water. The dichloromethane layer was separated, dried over anhydrous magnesium sulfate and concentrated. The residue was pure enough without further purification and was identified as the desired product, (S)-2-azidomethyl-2,3,8,9-tetrahydro-7H-1,4-dioxino[2,3-e]indol-8-one. An aliquot amount of the azide (0.8 g, 3.2 mmole) in ethanol (50 ml) was hydrogenated with 10% palladium on carbon (100 mg) for 15 hours. The resulting mixture was acidified with 4N isopropanolic HCl until pH<3. The catalyst was then filtered off and the filtrate was concentrated. The residue was dissolved in 90% aqueous ethanol and precipitated with diethyl ether to give the (S) enantiomer of the title compound as a white solid hydrochloride, 1.25 hydrate, (0.7 g, 85%), m.p. 278°-280° C.

Provenance & Evidence