反应详情

Trimethylsilyldiazomethane 2M in ether (5.7 ml, 11.4 mmole, 1.4 eq.) is added dropwise at RT to a suspension of 3,6-dimethyl-pyridine-2-carboxylic acid (containing potassium chloride) (3.07 g à 25%, 8.12 mmole, 1 eq.) in benzene (24 ml) and methanol (8 ml), and the yellow suspension is stirred at RT for 1.5 h. The yellow mixture is diluted with ethyl actate, washed once with sat. aqueous sodium bicarbonate sol., once with water, once with brine, dried with magnesium sulfate and the solvents are removed in vacuo. Purification of the residue (914 mg) by chromatography on a 20 g Silicycle silica cartridge (eluent heptane/ethyl acetate 5-40% 20 min) affords 3,6-dimethyl-pyridine-2-carboxylic acid methyl ester (714 mg, 53.2%) as a colorless liquid. MS (m/e)=166.3 [M+H+].

1. washwashed once with sat. aqueous sodium bicarbonate sol., once with water, once with brine
2. dry with materialdried with magnesium sulfate
3. customthe solvents are removed in vacuo
4. customPurification of the residue (914 mg) by chromatography on a 20 g Silicycle silica cartridge (eluent heptane/ethyl acetate 5-40% 20 min)