p-Toluenesulfonic acid → HCID 15672406, compound

Participants

Reaction Conditions

Reaction Steps

A solution of dimethyl 5-formylpyridine-2,3-dicarboxylate (0.75 g, 0.0036 mol), N-methylethylene diamine (0.38 mL, 0.0044 mol) and a catalytic amount of para-toluenesulfonic acid in toluene (10 mL) is heated at reflux temperature for 3 hours. During this process, water is removed by placement of an addition funnel containing 3 angstrom molecular sieves between the reaction flask and the reflux condensor. The reaction mixture is concentrated in vacuo, dissolved in methylene chloride (30 mL) and is washed with saturated aqueous sodium bicarbonate solution. The organic solution is dried over anhydrous magnesium sulfate and concentrated in vacuo to give a residue. The residue is dissolved in pyridine (10 mL) at 0° C. and treated with acetic anhydride (0.34 mL, 0.0036 mol). The reaction mixture is stirred for 1 hour at 0° C. and for 66 hours at room temperature. The pyridine is removed in vacuo to yield an oil. The oil is dissolved in methylene chloride and washed with saturated aqueous sodium bicarbonate. The organic solution is dried over anhydrous magnesium sulfate, concentrated in vacuo and purified by chromatography using silica gel and 10% triethylamine in ethyl acetate as eluant to yield the title compound (0.66 g, 56%) as a yellow oil, identified by IR and NMR spectral analyses.

Provenance & Evidence