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

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.

1. stirringthe mixture was stirred at −45° C. for 1 hr
2. waitat room temperature for 2 hr
3. customto quench
4. customthe reaction, tetrahydrofuran
5. customwas evaporated
6. customevaporator
7. extractionthe mixture was extracted with ethyl acetate
8. washThe extract was washed with saturated brine
9. dry with materialdried over magnesium sulfate
10. concentrationconcentrated under reduced pressure
11. customThe residue was purified by silica gel column chromatography (10% ethyl acetate/hexane)

ORD-Eintrag

ord-6732c9e518f34550adbf4a07e6fe20f3

Quelldatensatz

uspto-grants-2012_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08309580B2