I'm looking to synthesize a fairly simple mesylate, and had a question about reaction conditions. The two methods I've seen to make them:
1. Alcohol + methanesulfonyl chloride + TEA. TEA is removed either by washing with 1M HCl or washing with NaHCO3 and removing by rotovapping.
2. Alcohol + methanesulfonic anhydride + pyridine + dimethylaminopyridine.
My question is what are the pros and cons of each route. Methanesulfonic anhydride seems like it would be less toxic/dangerous to work with, and the reactions conditions are more mild although it takes longer.
Any thoughts would be appreciated.