Water → 3-Bromomethyl-7-(2,6-difluorobenzyl)-4,7-dihydro-5-isobutyryl-2-(4-nitrophenyl)-4-oxothieno[2,3-b]pyridine

Participants

Reaction Conditions

Reaction Steps

The compound obtained in Example 16 (1 g) was dissolved in methanesulfonic acid (5 ml) with cooling at 10 to 12° C. and then treated dropwise with a solution of sodium nitrate (0.165 g) in methanesulfonic acid (2.5 ml). The mixture was stirred as it was for 2 hours, and then poured into a cool water, and the crystal precipitated was recovered by a filtration, washed with water and diisopropylether, dried in vacuo to obtain a crude crystal (1.04 g). This was suspended in ethyl acetate (15 ml) with stirring and then cooled on ice, and the crystal precipitated was recovered by a filtration, washed with a cool ethyl acetate to obtain the title compound (0.647 g, 59.5%).

Provenance & Evidence