Triethylamine → 6-methoxy-3,4,4a,5,10,10a-hexahydro-2H-naphtho-[2,3-b][1,4]oxazine-4-carboxylic acid benzyl ester

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Reaction Conditions

Reaction Steps

To a solution of 6-methoxy-3,4,4a,5,10,10 a-hexahydro-2H-naphtho-[2,3-b][1,4]oxazine (0.62 g, 2.7 mmol) in 10 ml of CH2Cl2 was added triethylamine (1.0 ml, 7.2 mmol ) and benzyl chloroformate (0.6 ml, 4.1 mmol). The resulting mixture was stirred at 25° C. for 3 h. It was then diluted with 100 ml of EtOAc and washed with brine. The organic layer was dried over Na2SO4 and concentrated in vacuo, yielding an oily residue which was subjected to column chromatography (20% EtOAc-CH2Cl2) to provide 0.46 g (48%) of the desired product. 1H NMR (300 MHz, CDCl3): δ 2.45 (dd, 1H, J=10.6, 16.6 Hz), 2.83 (dd, 1H, J=10.3, 16.0 Hz), 3.04 (dd, 1H, J=5.0, 16.0 Hz), 3.68-3.88 (m, 6H), 3.76 (s, 3H), 4.02(m, 1H), 5.16 (AB q, 2H, J=17.6 Hz), 6.66 (m, 2H), 7.09 (t, 1H,J=7.8 Hz).

Provenance & Evidence