Reaction Steps
A 7 ml vial was charged with 4-(3-iodo-2(S)-methyl-propyl)-4H-benzo[1,4]oxazin-3-one (330 mg, 1.0 mmol), crude 3-ethoxyimino-8-azonia-bicyclo[3.2.1]octane chloride (200 mg, 0.98 mmol), and K2CO3 (290 mg, 2.1 mmol) in dry DMF (4 ml) and the reaction was shaken at 60° C. for 3 days. The reaction was then poured into water and extracted with ether. The combined organic phases were washed brine, dried (Na2SO4), filtered, concentrated under reduced pressure and the oily residue was purified by flash column chromatography (SiO2; CH2Cl2/acetone/MeOH, 90:7:3) to yield the diastereomeric mixture of the title compound as an oil (87 mg, 0.24 mmol, 24%). 1H NMR (CD3OD) δ 7.28 (dd, J=2.0, 7.6 Hz, 1H), 7.07-6.93 (m, 3H), 4.57 (ABq, J=14.8, 19.6 Hz, 2H), 4.12 (dd, J=6.4, 14.4 Hz, 1H), 4.05-3.92 (m, 3H), 3.30-3.16 (m, 2H), 2.92-2.82 (m, 1H), 2.54-2.32 (m, 3H), 2.18-1.81 (m, 2H), 1.60-1.34 (m, 2H), 1.20 (m, 3H), 0.93 (d, J=6.8H); 13C NMR (CD3OD) δ165.8, 156.6, 146.0, 128.6, 124.0, 122.6, 116.8, 115.9, 68.5, 67.4, 60.2, 59.54, 59.48, 58.8, 56.5, 45.0, 37.0, 36.9, 31.9, 31.7, 30.99, 30.96, 27.6, 27.0, 26.7, 26.1, 15.9, 13.7; HPLC-MS (ammonium acetate) [M+H]+=372.21.
