Methyl iodide → (4-Methylamino-phenyl)-(1,3,3-trimethyl-6-aza-bicyclo[3.2.1]oct-6-yl)-methanone

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Reaction Steps

To a solution of [4-(1,3,3-trimethyl-6-aza-bicyclo[3.2.1]octane-6-carbonyl)-phenyl]carbamic acid tert-butyl ester (2.6 g, 6.98 mmol) in dry DMF (75 ml) was added NaH (0.35 g, 8.38 mmol 60% in mineral oil) and the resulting mixture was stirred for 1 hr. Methyl iodide (521 μl, 8.38 mmol) was added and the stirring was continued for an additional 1 hr. The reaction mixture was quenched with water (50 ml) followed by extraction with diethyl ether (2×50 ml). The combined organic phases were washed with saturated aqueous ammonium chloride, dried (Na2SO4), filtered and evaporated in vacuo. The residue was dissolved in DCM (40 ml) and TFA (25 ml) was added. The resulting mixture was stirred for 18 hrs. at room temperature and evaporated in vacuo. To the residue was added water (10 ml) and the pH was adjusted to 9 by addition of 1 N sodium hydroxide. The aqueous phase was extracted with diethyl ether (2×25 ml) and the combined organic phases were dried (Na2SO4), filtered and evaporated in vacuo affording 2.5 g crude product which was purified by column chromatography (silica gel) using a mixture of EtOAc-Heptane (1:1) as eluent. Pure fractions were collected and evaporated to dryness affording a slowly crystallizing oil which was washed with diethyl ether (10 ml), filtered off and dried in vacuo at 50° C. afforded 0.9 g (45%) of the title compound as a solid.

Provenance & Evidence