Purifying amines on silica

I had good results with chloroform-methanol-ammonia mixtures for purifying amines and other polar tailing stuff on silica. Some people claim that anhydrous ammonia in methanol instead of aqueous conc. ammonia works even better – but I personally found no difference. Few good ratios of CHCl3-MeOH-conc.NH4OH are here: (ordered by increasing polarity) 100:10:1 80:10:1 80:15:1.5 80:25:2.5 80:35:4 (this is … Continue reading Purifying amines on silica