[Cl:1][C:2]1[N:10]=[C:9]([CH3:11])[CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[CH3:12]N(C=O)C.C(Cl)(=O)C(Cl)=O>ClCCl>[Cl:1][C:2]1[N:10]=[C:9]([CH3:11])[CH:8]=[CH:7][C:3]=1[C:4]([O:6][CH3:12])=[O:5]To a suspension of 2-chloro-6-methylnicotinic acid (5.3 g, 30.8 mmol) in dichloromethane (100 ml) at 0° C. were added DMF (1 ml) and oxalyl chloride (3.2 ml, 36.9 mmol). The mixture was allowed to warmn to room temperature and stirred for 5 h. The solvents were removed in vacuo and the residue was dissolved in dichloromethane (50 ml) and methanol (50 ml). The mixture was stirred at room temperature for 18 h and then concentrated in vacuo. The residue was dissolved in chloroform, washed with saturated sodium bicarbonate solution and brine, dried over MgSO4, and concentrated in vacuo to give a brown oil; yield 5.70 g (100%).
Wird geladen…