[Synthesis]
Example 3.2: Preparation of 2-methyl-6-(methylsulfonyl)pyridin-3-amine (Method 1); 6-bromo-2-methylpyridin-3-amine (40.0 g, 214 mmol), sodium methanesulfinate (87.3 g, 855 mmol), copper(I)-benzene trifluoromethanesulfonate complex (10.8 g, 21.4 mmol), and N1,N2-dimethyl Ethane-1,2-diamine (10.8 g, 21.4 mmol) in a solution of DMSO (300 mL) was heated at 150 °C for 4 hours. After the reaction was completed, it was cooled to room temperature and H2O (100 mL) was added. The dark brown solution was extracted with ethyl acetate (6 x 30 mL). The organic layer was washed with H2O (100 mL) to remove DMSO. the aqueous layer was back-extracted three times with ethyl acetate. All organic layers were combined, washed with brine, dried over Na2SO4 and filtered. After concentrating the filtrate under reduced pressure to about 200 mL, the solid product precipitated and was collected by filtration to give the title compound (24.0 g, 60% yield) as a brown powder. The compound was characterized by LC-MS and 1H NMR: the exact mass of C7H10N2O2S was calculated to be 186.1 and the measured LC-MS m/z was 187.1 (M+H)+; 1H NMR (400 MHz, CDCl3) δ 2.44 (s, 3H), 3.13 (s, 3H), 4.66 (bs, 2H), 7.01 (d, J=), 8.34 Hz, 1H. 8.34 Hz, 1H), 7.71 (d, J=8.34 Hz, 1H). |