1-Benzyl-4-piperidone → 1-benzyl-6'-bromo-3',4'-dihydro-spiro[piperidine-4,2'(1H)-quinazoline]-4'-one

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Reaction Steps

N-benzyl 4-piperidone (1.76 g, 9.3 mmol) and concentrated H2SO4 (2 drops) were added to a solution of 2-amino-5-bromo-benzamide (2 g, 9.3 mmol) dissolved in acetic acid (15 ml). The mixture was stirred at RT for 2 h, then poured into ice water and brought to a pH value of 8-9 with saturated NaHCO3. The white precipitate was filtered off and washed with water, giving 1-benzyl-6′-bromo-3′,4′-dihydro-spiro[piperidine-4,2′(1H)-quinazoline]-4′-one (1.05 g).

Provenance & Evidence