Methyl iodide → 8-chloro-6-(2-chlorophenyl)-1,2-dihydro-2-methyl-1-oxo-4H-imidazo[1,5-a][1,4]benzodiazepin-3-carboxylic acid methyl ester ethanolate

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Reaction Steps

A mixture of 1.1 g (0.02 mole) of sodium methylate and 4 g (0.01 mole) of 8-chloro-6-(2-chlorophenyl)-1,2-dihydro-1-oxo-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid methyl ester in 100 ml of methanol was stirred under a drying tube for 30 min. The resulting pale yellow solution was treated with 5 ml of methyl iodide and stirred 5 hours longer at room temperature. After acidifying with acetic acid, the mixture was evaporated to dryness. The brown residue was partitioned between methylene chloride and water and the organic phase was separated, dried and evaporated to give a tan foam. Stirring the residue with 25 ml of ethanol gave a light tan solid. The solid was filtered, washed with a little ethanol and then with petroleum ether. Air drying on the funnel gave end product with mp ca. 120°. Recrystallization from ethanol gave off-white plates with mp 120°-125° (dec) which contained 1 mole of ethanol according to the analytical and spectral data. UV λ sh 212 mμ (ε=41000) max 281 (19800) ir (CHCl3) 1700 cm-1 (CO) 1720 (COOCH3) nmr (CDCl3) δ 3.60 ppm (s, 3, NCH3) 3.90 (s, 3, OCH3) 4.07 (d, 1) and 5.83 (d, 1) (AB-system, J=12 Hz, C4 --H) 7.05 (d, 1, J=2.5 Hz, C7 --H). 7.2-7.8 (m, 5, aromatic H) 8.03 (d, 1, J=8 Hz, C10 --H).

Provenance & Evidence