2'',3''-Dihydro-2''-oxospiro-[piperidine-4,4''(1H'')-quinazoline

635713-67-6

635713-68-7

The general procedure for the synthesis of 1'H-spiro[piperidine-4,4'-quinazolin]-2'(3'H)-ones was carried out as follows, using 1-benzyl-1'H-spiro[piperidine-4,4'-quinazolin]-2'(3'H)-ones as starting material: 1-benzyl-1'H-spiro[piperidine-4,4'-quinazolin]-2'(3'H)-ones (1.00 g) were dissolved in degassed methanol (50 ml ), 6N hydrochloric acid (2.0 ml) was added followed by 10% palladium carbon catalyst (150 mg). The reaction mixture was placed in a Parr hydrogenation unit and the reaction was shaken at 60 psi hydrogen pressure overnight. The progress of the reaction was monitored by LC/MS and the reaction was found to be incomplete. The 10% palladium carbon catalyst (200 mg) was added additionally and the reaction was continued with oscillation under the same conditions for 2 days. Upon completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated to afford the target product 1'H-spiro[piperidin-4,4'-quinazolin]-2'(3'H)-one (531 mg, 64% yield). Mass spectrometry analysis showed a molecular ion peak of 218.12 (MH+).