[CH3:1][N:2]([CH3:19])[S:3]([CH2:6][CH2:7][NH:8][C:9]1[C:10]([C:15]([O:17]C)=O)=[N:11][CH:12]=[CH:13][CH:14]=1)(=[O:5])=[O:4].[H-].[Na+].Cl[C:23](=[O:29])[CH2:24][C:25]([O:27][CH3:28])=[O:26]>C1COCC1.CO>[CH3:19][N:2]([CH3:1])[S:3]([CH2:6][CH2:7][N:8]1[C:9]2[C:10](=[N:11][CH:12]=[CH:13][CH:14]=2)[C:15]([OH:17])=[C:24]([C:25]([O:27][CH3:28])=[O:26])[C:23]1=[O:29])(=[O:4])=[O:5]Methyl 3-({2-[(dimethylamino)sulfonyl]ethyl}amino)pyridine-2-carboxylate (0.877 g, 3.05 mmol) was dissolved in dry THF (10 mL) and cooled to 0° C. NaH (338 mg, 60% suspension in oil, 8.45 mmol) was added and a precipitate formed. The slurry was treated with methyl 3-chloro-3-oxopropionate (0.410 mL, 3.82 mmol) and 3 drops of MeOH and allowed to warm and stir overnight. The reaction was concentrated somewhat in vacuo, then poured into water. The mixture was extracted once with CHCL3, then acidified and extracted repeatedly with CHCl3 until only a trace of UV active material is removed. The acidic organic extracts were dried over Na2SO4, filtered and evaporated to give the product as a pink foam.
불러오는 중…