Sodium Hydroxide → HCID 14374295, compound

Participants

Reaction Conditions

Reaction Steps

A mixture of 16.90 g (0.063 mol) of 4-[3-(1-piperidinyl)-propyl]piperidinoacetic acid and 2.0 g of a 75% sodium hydride dispersion in paraffin oil is heated in 160 ml of dimethylformamide at 50°-80° C. until the development of hydrogen has ended. To the resulting sodium salt of the above-mentioned acid are added 13.0 g (0.062 mol) of 5,11-dihydro-6H-pyrido[2,3-b][1,4]benzodiazepin- 6-one and at -10° C. 9.8 g (0.064 mol) of phosphorus oxychloride are added dropwise within 10 minutes. The resulting mixture is stirred for 4 hours at -10° C., for 4 hours at 0° C. and for 20 hours at ambient temperature. Then the mixture is stirred into 300 g of ice, adjusted to pH 9 with sodium hydroxide solution and extracted exhaustively with dichloromethane. The combined organic phases are washed once with a little ice water, dried over sodium sulphate and concentrated by evaporation. The residue is recrystallised from ethyl acetate using activated charcoal. Colourless crystals, m.p. 202°-203° C., totally identical to a sample obtained in Example 3 according to thin layer chromatography, mixed melting point, IR, UV and 1H-NMR spectra. Yield: 4.57 g (16% of theory).

Provenance & Evidence