* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With ammonium hydroxide; anhydrous phosphorus trichloride; chlorine; In water; acetone; toluene;
EXAMPLE 4 4-Chloropyridine-3-sulphonamide 137 g phosphorus trichloride are taken. While stirring, they are added to a solution of 56.3 g (0.32 mol) <strong>[51498-37-4]4-hydroxypyridine-3-sulphonic acid</strong> and heated to reflux at about 77 C. 44.5 g (0.62 mol) chlorine are then passed in within 3 to 4 hours, whereby the reflux temperature gradually increases. While stirring, post-reaction is allowed for 20 hours, whereby the temperature increases to 105 to 110 C. and the yellowish solution becomes almost clear. It is then cooled to about 50 C. and phosphorus oxychioride and PCl3 completely distilled off under vacuum. The distillation residue is mixed with 200 ml toluene, filtered at 20 to 25 C. and the filter residue again washed with a little toluene. The organic phase is stirred out twice with, in each case, 100 ml water and the aqueous phase separated off. The toluene phase is mixed with 30 ml acetone and 52 to 55 ml (0.67-0.7 mol) of a 24% aqueous ammonia solution added drop-wise at 20 to 25 C. with stirring within about 3 hours. It is further stirred for 9 hours, whereby the pH value of the solution at the end of the reaction lies at about 9. The precipitated product is filtered off with suction and washed chloride-free 3 times with, in each case, 50 ml water and subsequently washed twice with, in each case, 50 ml toluene.
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
For Research Only
120K+ Compounds
Competitive Price
1-2 Day Shipping
