Benzyl Bromide → Benzyl propiolate

To a solution of 17.0 g (233 mmol) of propiolic acid in 600 mL of anhydrous DMF was added 39.9 g (233 mmol) of benzyl bromide followed by portionwise addition of 76.0 g (233 mmol) of Cs2CO3. After stirring at room temperature for 24 h, the reaction was quenched with a saturated aqueous ammonium chloride solution and extracted with EtOAc (3×200 mL). The combined extracts were washed with water then brine and dried over anhydrous sodium sulfate. The mixture was then filtered through a silica gel pad washing with hexanes, and the filtrate was evaporated under reduced pressure to afford a crude product. The crude product was purified by silica gel chromatography eluting with a 0-20% ethyl acetate in hexane gradient to afford the title compound as a colorless oil (13.8 g, 35%). 1H NMR (CDCl3, 500 MHz) δ 7.41 (m, 5H), 5.25 (s, 2H), 2.92 (s, 1H).

1. customthe reaction was quenched with a saturated aqueous ammonium chloride solution
2. extractionextracted with EtOAc (3×200 mL)
3. washThe combined extracts were washed with water
4. dry with materialbrine and dried over anhydrous sodium sulfate
5. filtrationThe mixture was then filtered through a silica gel pad
6. washwashing with hexanes
7. customthe filtrate was evaporated under reduced pressure
8. customto afford a crude product
9. customThe crude product was purified by silica gel chromatography
10. washeluting with a 0-20% ethyl acetate in hexane gradient

ORD record

ord-57851859c4324cf18eba98e52226e682

Source dataset

uspto-grants-2014_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08653260B2