Ethyl propiolate → Ethyl 4-hydroxy-4-(3,4,5-trimethoxy-2-nitrophenyl)-2-butynoate

Temperature

-58 °C

A 1.0 M solution (1.9 ml) of lithium bistrimethylsilylamide in tetrahydrofuran was added to tetrahydrofuran (4.0 ml) at -78° C. under an argon atmosphere, and the mixture was stirred for 30 min. A solution of ethyl propiolate (176 μl, 1.74 mmol) in tetrahydrofuran (1.0 ml) was added thereto, and the mixture was stirred for 30 min. A solution of 3,4,5-trimethoxy-2-nitrobenzaldehyde (280 mg, 1.16 mmol), prepared in the step (b), in tetrahydrofuran (2.5 ml) was added thereto, and the temperature was raised to -58° C., followed by stirring for 30 min. The reaction mixture was poured into an ice-cold 10% aqueous ammonium chloride solution, and the mixture was vigorously stirred for 5 min. The reaction mixture was extracted with ethyl acetate, and the organic layer was washed with saturated brine and dried over anhydrous magnesium sulfate. The solvent was removed under reduced pressure to give ethyl 4-hydroxy-4-(3,4,5-trimethoxy-2-nitrophenyl)-2-butynoate as an oil (268 mg, 68%).

1. stirringthe mixture was stirred for 30 min
2. additionwas added
3. stirringby stirring for 30 min
4. stirringthe mixture was vigorously stirred for 5 min
5. extractionThe reaction mixture was extracted with ethyl acetate
6. washthe organic layer was washed with saturated brine
7. dry with materialdried over anhydrous magnesium sulfate
8. customThe solvent was removed under reduced pressure

ORD record

ord-4110a909f8b34625b996745238c8e886

Source dataset

uspto-grants-2000_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06093714