madhandevireddy - 27-7-2016 at 00:21
Hi, Mesylation of Diamines ,we r using reagents like MSA&MSC , Base(TEA,Pyridine,Dmf)
But the reactions is not proceed.plz help which reagent is best.
[Edited on 27-7-2016 by madhandevireddy]
CRUSTY - 28-7-2016 at 19:46
You've got to be way more specific and clear about what part of the reaction is not proceeding. Also, best reagent(s) for time efficiency, yield,
cost, or what?
madhandevireddy - 29-7-2016 at 02:19
I am doing Dofetilide synthesis .The final stage is conversion of NH2 to NHMS,i was using reagents like methane sulphonyl chloride & methane
sulfonic an hydride but reaction is not completed (starting product).
AvBaeyer - 29-7-2016 at 19:19
There are a few tricks known to those "skilled in the art" for running successful mesylations. Most important is good temperature control and
attention to the order and rate of addition of reactants. Typically, the compound to be mesylated is dissolved in a suitable solvent (dichloromethane
is a good one) and then well chilled in an ice bath. Triethylamine in about 10% molar excess is added and cooloing continued. Mesyl chloride in
dichloromethane is then added dropwise with care to maintain the reaction temperature at 10 C or lower. The reaction can be followed by tlc and when
starting substrate is gone, the reaction is worked up in a suitable fashion.
AvB
madhandevireddy - 3-8-2016 at 03:42
Hi thanks for your response,But we done the reaction with temp -10 to 0 C butthe addition of mesyl chloride with Dcm gum type black solid appeared
then reaction is not completed( TLC).