Hydrochloric Acid → Ethyl 2-ethyl-5-formylthiophene-3-carboxylate

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Reaction Steps

To a solution of ethyl 5-bromo-2-ethylthiophene-3-carboxylate (10.0 g) synthesized in Example 69 (4) in tetrahydrofuran (100 was added dropwise 1.0M isopropylmagnesium bromide-tetrahydrofuran solution (45.6 mL) at −45° C., and the mixture was stirred for 2 hr under an argon atmosphere. N,N-Dimethylformamide (8.80 mL) was added, and the mixture was stirred at −45° C. for 1 hr, and then at room temperature for 2 hr. 1N Hydrochloric acid was added to quench the reaction, tetrahydrofuran was evaporated using evaporator, and the mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (10% ethyl acetate/hexane) to give the title compound (7.82 g, 97%) as a yellow oil.

Provenance & Evidence