Potassium Phosphate, Tribasic → Methyl 3,4-dimethylthiophene-2-carboxylate

Participants

Reaction Conditions

Reaction Steps

Methyl boronic acid (0.94 g, 16.02 mmol), potassium phosphate (6.8 g, 32.04 mmol) and BINAP (1.33 g, 2.14 mmol) were added to a solution of methyl 3-bromo-4-methylthiophene-2-carboxylate (Prepared according to the procedure reported in Bioorganic Med. Chem. Lett., 2007, 15, 5, 2127-2146, 2.5 g, 10.68 mmol) in a toluene (60 ml) in a tube at 25° C. Nitrogen gas was bubbled through reaction mixture for 15 minutes. Palladium acetate (0.24 g, 1.07 mmol) was added to the reaction mixture under nitrogen and the tube was sealed. The reaction mixture was heated at 95-100° C. for 20 hr under stirring. The progress of the reaction was monitored by TLC. The reaction mixture was cooled to 25° C. and filtered through celite. The celite cake was washed with ethyl acetate (100 ml). The combined filtrate was concentrated under reduced pressure to obtain residue, which was dissolved in ethyl acetate (150 ml) and washed with water (2×30 ml). The separated organic layer was dried over sodium sulphate and concentrated under reduced pressure to obtain a crude product, which was purified by column chromatography using 5% ethyl acetate in hexanes as an eluent to obtain the title compound 9a (1.32 g, 73%).

Provenance & Evidence