2-Amino-5-methylpyridine → 2-aMino-5-Methylpyridine-3-sulfonyl chloride
Reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][C:5]([CH3:8])=[CH:4][N:3]=1.[Cl:9][S:10](O)(=[O:12])=[O:11].C(=O)(O)[O-].[Na+]>>[NH2:1][C:2]1[C:7]([S:10]([Cl:9])(=[O:12])=[O:11])=[CH:6][C:5]([CH3:8])=[CH:4][N:3]=1Participants
4
Conditions
- Temperature
- 140 °C
Procedure
Solid 2-amino-5-picoline (10.8 g, 0.10 mol) was added portionwise to chlorosulfonic acid (66 mL, 1.0 mol) at ambient temperature over 5 minutes. When the addition was complete, the mixture was warmed to 140° C. and stirred at that temperature for 2 hours. During the heating period gas evolution was initially rapid and ceased completely after 2 hours. The mixture was then cooled to room temperature and poured onto 2 liters of ice. Solid sodium bicarbonate was added to the resulting solution to adjust the pH to about 7.0. The solid product that precipitated was collected and rinsed with a small amount of cold ethanol. The solid was then dissolved in one liter of hot chloroform, the resulting solution was dried (magnesium sulfate), and the solution was concentrated to a volume of about 100 mL. The solid product that formed was collected, the mother liquor was concentrated to 20 mL and a second crop was collected. The solid products were combined to give the title compound (14.4 g, 70 %); m.p. 16°-166° C.