反应详情

温度

0 °C

A solution of O-(phenylmethyl)-L-serine (21.6 g, 0.108 mol) in aqueous sulfuric acid (786 ml, 2.5N) containing sodium bromide (69.3 g, 6.0 eq) was cooled to 0° C. in an ice bath. Sodium nitrite (21 g, 2.7 eq) was added over 10 minutes, and the solution stirred at 0° C. for one hour. The cooling bath was removed, ether (250 ml) was added, and stirring was continued overnight at room temperature. The aqueous layer was extracted repetitively with ether (3×100 ml), and the combined extracts were dried over anhydrous magnesium sulfate and evaporated under reduced pressure to give 25 g of a crude product. The product was purified by column chromatography (83:17; petroleum ether:ethyl acetate) to yield the title compound (10.6 g).

1. customThe cooling bath was removed
2. additionether (250 ml) was added
3. stirringstirring
4. waitwas continued overnight at room temperature
5. extractionThe aqueous layer was extracted repetitively with ether (3×100 ml)
6. dry with materialthe combined extracts were dried over anhydrous magnesium sulfate
7. customevaporated under reduced pressure
8. customto give 25 g of a crude product
9. customThe product was purified by column chromatography (83:17; petroleum ether:ethyl acetate)