2-(1-methylpiperidin-4-yl)acetyl chloride

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:40.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A solution of 2.2 gm (0.01 mol) of 4,9-dihydro-10H-thieno[3,4-b][1,5]benzodiazepin-10-one in 50 ml of dioxane and 10 ml of pyridine was mixed at ambient temperature with a solution of 0.02 mol of (1-methyl-4-piperidinyl)acetyl chloride (prepared from the potassium salt of 1-methyl-4-piperidinylacetic acid by reaction with thionyl chloride) in 100 ml of dioxane. The mixture was heated at 40° C. for three hours, with stirring, and then at 80° C. for two hours. After the dioxane solution was poured off, the viscous residue was taken up in water, the resulting mixture was filtered, and the filtrate was rendered alkaline and extracted with methylene chloride. The extraction residue was purified by column chromatography [silica gel, eluant: ethyl acetate/methylene chloride (1:1); then with methylene chloride/cyclohexane/methanol/ammonia (102:23:23:3) as eluant]. The desired fraction was concentrated by evaporation in vacuo and the residue was recrystallized from ethyl acetate. the resulting mixture was filtered extracted with methylene chloride The extraction residue was purified by column chromatography [silica gel, eluant The desired fraction was concentrated by evaporation in vacuo the residue was recrystallized from ethyl acetate