To the 1 ml DMF solution of 2-{1-[4-(4-Methoxy-benzenesulfonyl)-piperazin-1-yl]-ethyl}-3-methyl-4-oxo-3,4-dihydro-quinazoline-6-carbonitrile (10.0 mg, 0.02 mmol) was added sodium azide (16.7 mg, 0.24 mmol) and ammonium chloride (12.8 mg, 0.24 mmol). The reaction test tube was flushed with N2 and was irradiated at 200° C. for 40 minutes in the SmithSynthesizer Microwave Reactor with vigorous agitation by a magnetic stirrer. The mixture was cooled to room temperature, the solvent was removed by reduce pressure and extracted with water and ethyl acetate, dried over anhydrous MgSO4, and concentrated by rotary evaporation. Purification was accomplished by HPLC (Gilson-215, 0.035% TFA in acetonitrile and 0.05% water as mobile phase). The product was collected and dried under reduced pressure to give 2-{1-[4-(4-Methoxy-benzenesulfonyl)-piperazin-1-yl]-ethyl}-3-methyl-6-(1H-tetrazol-5-yl)-3H-quinazolin-4-one (Yield 3.09 mg, 9.8%). 1H NMR (400 MHz, MeOD-d4): δ 1.79 (d, 3H, J=6.57 Hz), 3.39-3.12 (m, 8H), 3.70 (s, 3H), 3.92 (s, 3H), 4.70 (s, br, 1H), 7.17 (d, 2H, J=9.09 Hz), 7.76 (d, 2H, J=9.09 Hz), 7.87 (d, 1H, J=8.59 Hz), 8.47 (dd, 1H, J=8.59, 1.77 Hz), 8.89 (d, 1H, J=1.77 Hz). MS m/z calc. 510.18 found (ESI); 511.4 (M+1)+. Retention time 2.2 minutes.
