Tributylphosphine → (E)-(S)-ethyl 3-{4-[3-(4-bromophenyl)-but-2-enyloxy]-phenyl}-2-ethoxy-propionate

Azodicarboxylic dipiperidide (0.756 g, 3.0 mmol) was added at 0-5°C. to a stirred solution of tributylphosphine (0.74 ml, 0.61 g, 3.0 mmol), (S)-ethyl 2-ethoxy-3-(4-hydroxyphenyl)-propionate (0.500 g, 2.10 mmol) and (E)-3-(4-bromophenyl)-but-2-en-1-ol (0.454 g, 2.0 mmol) in dry benzene (20 ml), the mixture warmed to room temperature, and stirred for 2.5 days. The resulting mixture was diluted with water and ethyl acetate (50 ml each), the aqueous layer collected and further extracted with ethyl acetate (50 ml). The organic layers were combined, washed with brine, dried (MgSO4) and evaporated. The crude product was then purified by column chromatography on silica gel (20% ethyl acetate in n-heptane eluent) to give (E)-(S)-ethyl 3-{4-[3-(4-bromophenyl)-but-2-enyloxy]-phenyl}-2-ethoxy-propionate as an oil; 0.780 g (87%).

1. customthe aqueous layer collected
2. extractionfurther extracted with ethyl acetate (50 ml)
3. washwashed with brine
4. dry with materialdried (MgSO4)
5. customevaporated
6. customThe crude product was then purified by column chromatography on silica gel (20% ethyl acetate in n-heptane eluent)

ORD-Eintrag

ord-cb91614824dc4177afe870a5e7cfa93b

Quelldatensatz

uspto-grants-2003_04

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06555577B1