Reaktion #74862

Reaktionsgleichung

5-(3-bromophenyl)-1-methyl-3-phenyl-4(1H)-pyridinone

methyl methanesulfonate

pyridinone

→

5-(3-bromophenyl)-4-methoxy-1-methyl-3-phenylpyridinium methanesulfonate

Lösungsmittel

benzene

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONA mixture of 4.0 g
2. 2
   Temperaturunder reflux for 6 hours
3. 3
   TemperaturThe mixture was cooled
4. 4
   Sonstigethe solvent removed in vacuo
5. 5
   Sonstigeto crystallize
6. 6
   SonstigeAfter the front-running spot was removed the column
7. 7
   Sonstigewas flushed with ethanol
8. 8
   Sonstigeremoved
9. 9
   SonstigeThe column was flushed with ethanol
10. 10
    Sonstigethe ethanol removed
11. 11
    Sonstigeto yield 0.75 g

Vorschrift

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.

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