Formaldehyde → 2-Acetoxyethyl 9-(2,3-Dichlorophenyl)-4,7-dimethyl-1,1-dioxo-2,3,4,5,6,9-hexahydropyrido[2,3-f][1,4]thiazepine-8-carboxylate

Participants

Reaction Steps

A mixture of 2-acetoxyethyl 9-(2,3-dichlorophenyl) -1,1-dioxo-2,3,4,5,6,9-hexahydro-7-methyl-pyrido[2,3-f][1,4]thiazepine-8-carboxylate (0.880 g, 1.69 mmole) from Example 19, and 1 mL of 38% aqueous formaldehyde solution in 20 mL of acetonitrile was treated with sodium cyanoborohydride (0.070 g, 1.69 mmole). After stirring for 1 hour, 0.5 mL of acetic acid was added, and the reaction was stirred for another 2 hours. After the addition of 40 mL of water and adjustment of the pH to 9 with 6N sodium hydroxide, the reaction was extracted with 3×30 mL of chloroform. The combined organic extracts were dried with sodium sulfate, the solvent was removed under reduced pressure, and the residue was chromatographed (2% methanol, 0.1% ammonia in chloroform on silica gel) to obtain the title compound (0.743 g, 82%).

Provenance & Evidence