Reaction Steps
Methanesulfonyl chloride (0.14 mL, 1.7 mmol) was added drop-wise to a stirred solution of alcohol 142 (347 mg, 1.42 mmol) and iPr2NEt (0.49 mL, 2.84 mmol) in DCM (25 mL) at 0° C., and the solution was stirred at 0° C. for 1 h. Water (25 mL) was added and the mixture extracted with EtOAc (3×30 mL). The organic fraction was washed with dilute Na2CO3 solution (25 mL) and water (25 mL). The organic solution was dried and the solvent evaporated to give a yellow solid, which was treated with morpholine (0.37 mL, 4.3 mmol) in DMF (10 mL) at 100-110° C. for 10 h. The solution was diluted with EtOAc (200 mL) and washed with Na2CO3 solution (50 mL) and water (30 mL). The organic solution was dried and the solvent evaporated. The residue was purified by chromatography, eluting with a gradient (50-70%) of EtOAc/pet. ether, to give 1-oxide 143 (398 mg, 89%) as a pale yellow solid: mp (EtOAc) 111-112° C.; 1H NMR δ 8.24 (s, 1H, H-9), 7.73 (s, 1H, H-5), 3.73 (t, J=4.6 Hz, 4H, 2×CH2O), 3.19-3.29 (m, 2H, CH2), 3.02 (q, J=7.6 Hz, 2H, CH2), 2.88-2.99 (m, 2H, CH2), 2.77-2.88 (m, 1H, H-7), 2.47 (t, J=4.6 Hz, 4H, 2×CH2N), 2.38 (d, J=7.6 Hz, 2H, CH2), 1.43 (t, J=7.6 Hz, 3H, CH3); 13C NMR δ 167.1, 153.6, 147.7, 147.6, 132.3, 123.1, 114.7, 67.0 (2), 63.3, 53.9 (2), 37.6, 37.3, 36.7, 30.6, 12.3. Anal. calcd for C17H22N4O2: C, 65.0; H, 7.1; N, 17.8. Found: C, 64.9; H, 7.1; N, 17.9%.
