Acetic Acid → HCID 22449904, compound

Participants

Reaction Steps

6-Amino-2,4-dioxo-1-[4-(4-diphenylmethoxypiperidino)butyl)-1,2,3,4-tetrahydroquinazoline (800 mg) obtained in Example 40 was suspended in methanol (8.0 ml), and to this mixture acetic acid (0.8 ml) and 37% formaldehyde (0.8 ml) were added and the mixture was stirred for 1.5 hours. A solution of sodium cyanoborohydride (141 mg) in methanol (4.0 ml) was added dropwise and the mixture was stirred at room temperature for 27 hours. The reaction mixture was concentrated under reduced pressure, diluted with ethyl acetate, washed with water, dried (Na2SO4) and then the solvent was distilled off under reduced pressure. The residue was subjected to a column chromatography on a silica gel eluting with n-hexane-ethyl acetate (5:1,v/v) to give the title compound (420 mg, 50%). Recrystallization from ethyl acetate-ethyl ether yielded a yellow crystal having a melting point of 165 to 167° C.

Provenance & Evidence