반응 #429457

반응 방정식

cesium carbonate

(S)-2-phthalimido-6-hydroxyhexanoic acid

benzyl bromide

→

title product

(S)-2-Phthalimido-6-hydroxyhexanoic acid, phenylmethyl ester

용매

dimethylformamide

반응 조건

후처리

1. 1
   기타the mixture was partitioned between ethyl acetate and water
2. 2
   추출The organic extract
3. 3
   세척was washed with water (twice) and brine
4. 4
   건조dried (sodium sulfate)
5. 5
   여과filtered
6. 6
   기타to give an oil
7. 7
   기타chromatographed (Merck silica gel, 6/4-ethyl acetate/hexane)
8. 8
   기타to give essentially pure product as a solid
9. 9
   기타Recrystallization from ethyl acetate/hexane
10. 10
    기타gave 7.173 g

실험 절차

A slurry of cesium carbonate (3.819 g, 11.7 mmol.) and (S)-2-phthalimido-6-hydroxyhexanoic acid (6.00 g, 21.6 mmol.) in dimethylformamide (60 ml.) was treated with benzyl bromide (3.30 ml., 4.75 g., 27.7 mmol.). After stirring at room temperature for 2 hours, the mixture was partitioned between ethyl acetate and water. The organic extract was washed with water (twice) and brine, then dried (sodium sulfate), filtered and stripped to give an oil. The oil was flash chromatographed (Merck silica gel, 6/4-ethyl acetate/hexane) to give essentially pure product as a solid. Recrystallization from ethyl acetate/hexane gave 7.173 g. (1st crop) and 394 mg. (2nd crop) for a total of 7.567 g. of pure title product; m.p. 106°-108.5° C; [α]D =-27.5° (c=1.5, methanol). TLC (75/25 ethyl acetate/hexanes) Rf =0.43.

출처