Ammonium Hydroxide → 3,4-dihydro-1-(4-piperidinyl)-2(1H)-Quinazolinone

Participants

Reaction Steps

To a solution of 1-(1-benzyl-4-piperidinyl)-3,4-dihydroquinazolin-2(1H)-one (947 g, 295 mmol) from Step 4 in dry dichloroethane (20 mL) was added 1-chloroethyl chloroformate (0.35 mL, 3.2 mmol). The reaction was refluxed for 3 h. The solvent was rmoved under reduced pressure and the residue was dissolved in MeOH (50 mL) and the solution was refluxed for 1 h. The reaction was cooled to ambient temperature, conc. NH4OH (1 mL) was added, and the solvent was removed under reduced pressure. The residue was purified by pressurized silica gel column chromatography using 90:10:1 CHCl3 :MeOH:NH4OH as eluant. 1-(4-Piperidinyl)-3,4-dihydroquinazolin-2(1H)-one was obtained as an oil (48% yield).

Provenance & Evidence