Boron tribromide → Ethyl 2-(4-hydroxyphenyl)cyclopropane-1-carboxylate

Temperature

0 °C

To a 50 mL RB flask fitted with magnetic stirrer was charged with 20 mL of dichloromethane. To the stirred solvent was added ethyl 2-(4-methoxyphenyl)cyclopropanecarboxylate (0.9 g, 4 mmol). The reaction mixture was cooled to 0° C. and boron tribromide (0.9 mL) was added drop wise, stirred for 30 minutes at the same temperature. The reaction mixture was quenched by the addition of ethanol drop wise at 0° C. The reaction mixture was concentrated to distill off the solvent; water was added to the crude and extracted with ethyl acetate. The organic layer was washed with saturated solution of NaHCO3 (25 mL), followed by brine solution (25 mL). The organic layer was dried over anhydrous Na2SO4 and the solvent was removed under reduced pressure. The product was obtained as pale yellow liquid (0.3 g, yield: 35.6%). 1H NMR (300 MHz, DMSO-d6): δ 9.27 (s, 1H), 6.94-6.97 (d, 2H), 6.64-6.67 (d, 2H), 4.05-4.12 (q, 2H), 2.28-2.36 (m, 1H), 1.75-1.80 (m, 1H), 1.35-1.41 (m, 2H), 1.15-1.28 (t, 3H).

1. customTo a 50 mL RB flask fitted with magnetic stirrer
2. customThe reaction mixture was quenched by the addition of ethanol drop wise at 0° C
3. concentrationThe reaction mixture was concentrated
4. distillationto distill off the solvent
5. additionwater was added to the crude
6. extractionextracted with ethyl acetate
7. washThe organic layer was washed with saturated solution of NaHCO3 (25 mL)
8. dry with materialThe organic layer was dried over anhydrous Na2SO4
9. customthe solvent was removed under reduced pressure

ORD record

ord-eb582b1deb2b4ed79674bb85204343fa

Source dataset

uspto-grants-2016_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09278915B2