4-Toluenesulfonyl chloride → Toluene-4-sulfonic acid 6-methyl-1-[1-(6-methyl-pyridin-3-yl)-ethyl]-2-oxo-1,2-dihydro-pyridin-4-yl ester

Participants

Reaction Steps

A stirred mixture of the product from Step 1 (475 mg, 1.947 mmol) and 4-methylbenzenesulfonyl chloride (371 mg, 1.947 mmol) in anhydrous dichloromethane (16 ml) was treated with anhydrous triethylamine (0.81 ml, 5.839 ml) and stirring was continued at ambient temperature for 18 h. The reaction mixture was diluted with dichloromethane (150 ml), washed with water (100 ml) followed by brine (100 ml) and dried (MgSO4). The solvent was removed in vacuo and the residue purified by flash silica chromatography eluting with ethyl acetate to give toluene-4-sulfonic acid 6-methyl-1-[1-(6-methyl-pyridin-3-yl)-ethyl]-2-oxo-1,2-dihydro-pyridin-4-yl ester (609 mg) as a colourless gum which solidified on standing. LC-MS m/z 399 [M+H]+ Rt=2.10 min.

Provenance & Evidence