... NMR (CDCl 3): 14,76 (s, 1H); 9,07(s, 1H, CH- 4); 7,79(td, 1H, CH- 7); 5,02(td, 1H C- 3); 4,68(dd, 1H, CH2- 2); 4,50(dd, 1H, CH2- 2); 1,48(d, 3H c a 3-CH 3) 13 C NMR (CDCl 3): 176,4 6(7 -CO); 165,5 9(6 -COO); ... 2.3.4.4 Nghiên c u nh hư ng c a lư ng dung môi ñ n hi u su t 3,45- 3,36(m, 4H); 2,56-2,55(m, 4H); 2,37 (s, 3H); 1,61 (d, 3H) ph n ng (b ng 2. 7) 13 H-NMR (CDC1 3): 8,62 (s, 1H); 7,70 (d, 1H ,); 4,53-4,35(m, ... s n ph m levofloxacin ñư c d ñ nh t ng h p qua nhi u bư c ñi qua h p ch t trung gian (- ) -(3 S)-7,8difluoro-3,4-dihydro-3-methyl-2H-[1,4]benzoxazine (g i t t h p ch t trung gian (- ) -(3 S)- methyl-benzoxacine...