Methyl iodide → 3-Fluoro-1,3-dihydro-1-methyl-7-chloro-5-phenyl-2H-1,4-benzodiazepin-2-one

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Reaction Steps

To a well stirred solution of 3.0 g (0.01 mol) of 3-fluoro-1,3-dihydro-7-chloro-5-phenyl-2H-1,4-benzodiazepin-2-one, 75 ml of dry THF and 25.56 g (0.18 mol, 11.2 ml) of methyl iodide was added a suspension of 0.48 g (0.02 mol) of sodium hydride in 20 ml of THF. There was an immediate evolution of hydrogen. The contents of the flask were stirred under a nitrogen atmosphere for exactly two hours. The product mixture was poured into approximately 100 ml of water and methylene chloride added to extract the product. The organic layer was separated and washed twice with ca. 50 ml portions of fresh water, and then allowed to dry over magnesium sulfate. Evaporation of the solvent under reduced pressure gave 1.38 g of a yellow crystalline material. Recrystallization from hot heptane gave 0.97 g of an off-white powder identified as 3-fluoro-1-(N-methyl)-7-chloro-5-phenyl-1,4-benzodiazepin-2-one: 1H nmr (DMSO-d6): δ7.2-7.72 ppm (m, 8H), δ 5.8 ppm (d, 1H, 56 Hz), δ 3.37 (m, 3H, N-methyl); 19F nmr (DMSO-d6) δ -160.14 ppm (d, J=56 Hz).

Provenance & Evidence