benzyl N-(4-hydroxy-4-methylcyclohexyl)carbamate → Trans-4-amino-1-methyl-cyclohexanol

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Reaction Steps

The compound obtained in Step 1 of this Reference Example was dissolved in ethanol (12 mL). To the solution, 10% palladium-carbon catalyst (hydrated, 400 mg) was added, and the mixture was stirred at room temperature for 15 hours under a hydrogen atmosphere at normal pressure. After filtration through celite, the filtrate was concentrated under reduced pressure to obtain a crude product of 4-amino-1-methylcyclohexanol. This crude product and ethyl 3-(dimethylamino)-2-isocyanoacrylate (450 mg) were mixed and stirred at 75° C. for 8 hours. To the reaction solution, saturated aqueous ammonium chloride was added, and organic matter was extracted with ethyl acetate. The organic layer was dried over anhydrous sodium sulfate and filtered, and the solvent was distilled off under reduced pressure. The residue was purified by silica gel column chromatography (eluting solvent: hexane/ethyl acetate=1/1-ethyl acetate) to obtain a diastereomeric mixture of the title compound (462 mg, trans:cis=1:3).

Provenance & Evidence