Cyclohexanemethylamine → 2-(Cyclohexylmethylamino-methyl)-2,3,8,9-tetrahydro-7H-1,4-dioxino[2,3-e]indol-8-one

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Reaction Conditions

Reaction Steps

(R)-2-(Toluene-4-sulfonyloxymethyl)-2,3,8,9-tetrahydro-7H-1,4-dioxino[2,3-e]indol-8-one (0.80 g, 2.13 mmole), and cyclohexylmethylamine (1.33 g, 11.7 mmole) were combined in 15 ml of dry DMSO and heated to 80° C. for 6 hours under a nitrogen atmosphere. The reaction was allowed to cool and was partitioned between 100 ml of ethyl acetate and 150 ml of deionized water. The organic layer was washed with brine, dried over MgSO4, filtered and concentrated to yield a black oil. This oil was column chromatographed on silica gel using 0.75% methanol/CH2Cl2 to remove impurities. A concentration of 2% methanol/CH2Cl2 eluted the desired product, which was as an oil (0.38 g, 56%) upon concentration in vacuum. This oil was crystallized from isopropanol with the addition of a solution of fumaric acid (0.15 g, 1.3 mmole) in hot isopropanol to give 0.39 g of the (S) enantiomer of the title compound as an off-white solid monofumarate, half hydrate, m.p. 187°-188° C.

Provenance & Evidence