Acetic Acid → HCID 22449844, compound

Participants

Reaction Steps

7-Amino-2,4-dioxo-1-[4-(4-diphenylmethoxypiperidino)butyl]-1,2,3,4-tetrahydroquinazoline (500 mg) obtained in Example 39 was suspended in methanol (5.00 ml), and to this mixture acetic acid (0.5 ml) and 37% formaldehyde (0.5 ml) were added and the mixture was stirred for 1 hour. A solution of sodium cyanoborohydride (94.5 mg) in methanol (2.0 ml) was added dropwise and the mixture was stirred at room temperature for 21 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 to give the title compound (378 mg, 72%) from a fraction eluted with n-hexane-ethyl acetate (5:1,v/v). Recrystallization from ethyl acetate-ethyl ether yielded a yellow crystal having a melting point of 203 to 204° C.

Provenance & Evidence