Potassium Carbonate → 3-chloro-2-methoxy-5-methyl-6,7,8,9-tetrahydro-5H-pyrido[2,3-d]azepine

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Reaction Conditions

Reaction Steps

A mixture of 2-methoxy-5-methyl-7-(trifluoroacetyl)-6,7,8,9-tetrahydro-5H-pyrido[2,3-d]azepine (100 mg, 347 μmol), PCl5 (722 mg, 3.47 mmol) and POCl3 (10 ml) was heated at 125° C. in a sealed tube for 16 h. The reaction mixture was parted between DCM and sat. aq. NaHCO3. The organic phase was washed with brine, dried over Na2SO4 and concentrated in vacuo. Chromatographic purification rendered 23.5 mg (21%) of 3-chloro-2-methoxy-5-methyl-7-(trifluoroacetyl)-6,7,8,9-tetrahydro-5H-pyrido[2,3-d]azepine. A mixture of 3-chloro-2-methoxy-5-methyl-7-(trifluoroacetyl)-6,7,8,9-tetrahydro-5H-pyrido[2,3-d]azepine (23.5 mg, 72.8 μmol) and K2CO3 (30 mg) in MeOH (7 ml) was heated at reflux for 2 h. The reaction mixture was concentrated in vacuo and chromatographic purification of the resulting residue rendered 11.2 mg (68%) of 3-chloro-2-methoxy-5-methyl-6,7,8,9-tetrahydro-5H-pyrido[2,3-d]azepine. 1H-NMR (CDCl3) δ 7.48 (s, 1H), 3.99 (s, 3H), 3.55-3.30 (m, 4H), 3.25 (m, 1H), 3.07 (m, 1H), 2.85 (dd, 1H), 1.43 (d, 3H) ppm.

Provenance & Evidence