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

HRID 1197

Reaction equation

HRID 1197 reaction equation
C(=O)([O-])[O-].[Cs+].[Cs+].[C:7]1(=[O:26])[N:11]([C@@H:12]([CH2:16][CH2:17][CH2:18][CH2:19][OH:20])[C:13]([OH:15])=[O:14])[C:10](=[O:21])[C:9]2=[CH:22][CH:23]=[CH:24][CH:25]=[C:8]12.[CH2:27](Br)[C:28]1[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=1>CN(C)C=O>[C:10]1(=[O:21])[N:11]([C@@H:12]([CH2:16][CH2:17][CH2:18][CH2:19][OH:20])[C:13]([O:15][CH2:27][C:28]2[CH:33]=[CH:32][CH:31]=[CH:30][CH:29]=2)=[O:14])[C:7](=[O:26])[C:8]2=[CH:25][CH:24]=[CH:23][CH:22]=[C:9]12

Participants

5

Reactant 3

HCID 7498Benzyl BromideHCID 10796Cesium carbonateHCID 11065730(S)-2-Phthalimido-6-hydroxyhexanoic acid

Product 1

HCID 13851095(S)-2-Phthalimido-6-hydroxyhexanoic acid, phenylmethyl ester

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

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.

Workup

  1. customthe mixture was partitioned between ethyl acetate and water
  2. extractionThe organic extract
  3. washwas washed with water (twice) and brine
  4. dry with materialdried (sodium sulfate)
  5. filtrationfiltered
  6. customto give an oil
  7. customchromatographed (Merck silica gel, 6/4-ethyl acetate/hexane)
  8. customto give essentially pure product as a solid
  9. customRecrystallization from ethyl acetate/hexane
  10. customgave 7.173 g

Sources & evidence

ORD record
ord-b0ab2ffb190f41a3906168de2e0367c1
Source dataset
uspto-grants-1998_03
Patent number
US05723457

Linked notes

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