Methyl Methanesulfonate → 5-(3-Bromophenyl)-4-methoxy-1-methyl-3-phenylpyridinium methanesulfonate

Participants

Reaction Steps

A mixture of 4.0 g. of 5-(3-bromophenyl)-1-methyl-3-phenyl-4(1H)-pyridinone and 20 ml. of methyl methanesulfonate in benzene was heated under reflux for 6 hours. The mixture was cooled and the solvent removed in vacuo. The product failed to crystallize. The product was passed over a silica gel column in ethyl acetate. After the front-running spot was removed the column was flushed with ethanol. The ethanol fractions were again placed on a silica gel solumn and front-running impurities removed. The column was flushed with ethanol and the ethanol removed to yield 0.75 g. of a hard glass. The nmr spectrum of the product was consistent with the structure of the expected salt. For example, there was an N-CH3 peak at 4.4 ppm and a peak at 8.7 ppm attributed to the hydrogens at the 2- and 6-positions of the pyridine ring. As is characteristic of pyridinium salts, both these peaks were shifted from the corresponding peaks in the starting pyridinone.

Provenance & Evidence