2-(2-Bromoethoxy)tetrahydro-2H-pyran → Methyl N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]-N-(2-hydroxyethyl)carbamate

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Reaction Steps

Methyl N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]-N-[2-(2-tetrahydropyranyloxy)ethyl]carbamate (Compound No. D1.119) was first prepared from methyl N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]carbamate (Compound No. C1.5, prepared as described in Example 21 below) and 2-(2-tetrahydropyranyloxy)ethyl bromide according to the general procedure of Example 13 above. A catalytic amount (approximately 10 mg) of p-toluenesulfonic acid monohydrate was added to a solution of 658.1 mg of the thus prepared methyl N-[4-(benzothiazol-2-ylmethoxy)-2-methylphenyl]-N-[2-(2-tetrahydropyranyloxy)ethyl]carbamate in 6.6 ml of methanol at room temperature. The resulting mixture was stirred for 2 hours at room temperature, and water was then added to the reaction mixture. The resulting mixture was extracted with ethyl acetate and the organic layer was washed consecutively with water and a saturated aqueous sodium chloride solution and then dried over anhydrous sodium sulfate. The solvent was then removed by evaporation under reduced pressure to give a residue which was purified by column chromatography through silica gel using a 1:2 by volume mixture of hexane and ethyl acetate as the eluent, to give 702.5 mg (yield 94.1%) of the title compound as a solid having a melting point of 109°-110° C.

Provenance & Evidence