Chloroform → (R)-7-Cyano-2,3,4,5-tetrahydro-1-[(1-methyl-1H-imidazol-5-yl)methyl]-4-(methylsulfonyl)-3-(phenylmethyl)-1H-1,4-benzodiazepine, monohydrochloride

Participants

Reaction Steps

To a solution of 200 mg (0.38 mmol) of (R)-7-cyano-2,3,4,5-tetrahydro-1-[(((1,1-dimethylethoxy)-carbonyl)-1H-imidazol-4-yl)methyl]-4-(methylsulfonyl)-3-(phenylmethyl)-1H-1,4-benzodiazepine (prepared from Example 224 as described for Compound A of Example 225) in 2 mL of methylene chloride, at -78° C. and under argon, was added dropwise 59 μL (0.48 mmol) of methyl triflate. The reaction was allowed to warm to rt, during which time a white precipitate was obtained. Stirring was continued at rt for 3 hr, after which time 140 μL (0.8 mmol) of DIEA was added and stirring continued overnight at rt. The mixture, without workup, was subjected to flash chromatography on a 30 cc column of silica gel. Elution with 2% MeOH--CHCl3 afforded 122 mg (0.28 mmol, 74%) of a clear colorless oil which crystallized on standing. This material was converted to its hydrochloride by the addition of 0.28 mL of 1M HCl in ether to a methylene chloride solution (2 mL) of the free base. A white precipitate was obtained which on filtration afforded 90 mg of Example 235 as a white powder.

Provenance & Evidence