p-Toluenesulfonic acid → HCID 19434003, compound

Participants

Reaction Steps

To a solution of the product of Step A (10.21 g, 29.9 mmol) in anhydrous THF (100 mL) and DMF (15 mL) at 0° C. was added sodium hydride (60% dispersion in mineral oil, 1.32 g, 32.9 mmol). After stirring for 30 min, methyl 2-bromoacetate (5.49 g, 35.9 mmol) was added and stirring continued at ambient temperature for 4 h. The reaction mixture was poured into a saturated solution of sodium bicarbonate (150 mL) and extracted with ethyl acetate (2×100 mL). The combined extracts was dried (MgSO4) and evaporated to give an oil which was dissolved in acetone (150 mL) and p-toluenesulfonic acid (2.5 g) was added. This solution was stirred at ambient temperature for 2 h, heated at reflux temperature for 5 h, cooled and mixed with water (100 mL) and sodium carbonate (1.0 g). Acetone was evaporated and the aqueous was extracted with ethyl acetate (2×100 mL). The combined extracts were dried (MgSO4) and evaporated to a residue which was purified by column chromatography (silica, 40% ethyl acetate/hexane) to give an oil (3.67 g, 33%).

Provenance & Evidence