反应详情

4-(1,4-Dioxa-8-aza-spiro[4.5]dec-8-yl)-benzoic acid(which was obtained in Example 150) (12.5 g, 47.5 mmol) was treated with concentrated hydrochloric acid (500 mL) at room temperature. After 15 hours ˜28% ammonium hydroxide was added dropwise and the precipitate was collected by filtration, and dried over phosphorus pentoxide to give the title compound as a white solid (9.2 g, 88%); 1H NMR (300 MHz, CDCl3) δ 2.46 (t, J=6.1 Hz, 4H), 3.74 (t, J=6.1 Hz, 4H), 7.02 (d, J=9.0 Hz, 2H), 7.80 (d, J=9.0 Hz, 2H); MS (ES) m/z: 219.8 (MH+); HRMS Calcd. for C12H14NO3 (MH+): 220.0974. Found: 220.0947.

1. filtrationthe precipitate was collected by filtration
2. dry with materialdried over phosphorus pentoxide