Benzyl Bromide → HCID 12597468, compound

HRID 248199Notes

Reaction equation

HRID 248199 reaction equation
[H-].[Na+].[C:3]([O:8][CH2:9][CH3:10])(=[O:7])[C@H:4]([CH3:6])O.[I-].[CH2:12](Br)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.[O:20]1CCCC1>>[C:12]([C@H:4]([CH3:6])[C:3]([O:8][CH2:9][CH3:10])=[O:7])(=[O:20])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

6

Reactant 5

HCID 7498Benzyl BromideHCID 8028Tetrahydrofuran3×HCID 24758Sodium hydrideHCID 30165Iodide IonHCID 92831(L)-ethyl lactate

Product 1

HCID 12597468HCID 12597468, compoundYield 75%

Conditions

Temperature
25 °C

Procedure

To a slurry of 3.13 g (93 mmol) of sodium hydride (60% in mineral oil) in tetrahydrofuran (150 mL) at 25° C. was added a solution of 10.0 g (85 mmol) of (S)-ethyl lactate (20) in tetrahydrofuran (50 mL) dropwise over a 30 min period under a nitrogen atmosphere. The resulting solution was then allowed to stir at 25° C. for an additional 30 min to ensure complete anion formation. To the anion was added 33.2 g (90 mmol) of tetra-n-butylammoniun iodide. A solution of 10.3 mL (93 mmol) of benzyl bromide in tetrahydrofuran (50 mL) was added dropwise to the reaction mixture over a 30 min period. The reaction was complete within 2 h at 25° C., during which time a solid precipitate formed. The reaction mixture was filtered through a coarse sintered glass funnel containing Celite. The solid was washed with diethyl ether (50 mL). The filtrate was washed with a saturated aqueous sodium chloride solution (3×300 mL) and dried (MgSO4). Concentration and purification by flash chromatography on silica gel (EM 60, 0.040-0.063 partical size, 230-400 Mesh, column size: 7 cm diameter×20 cm length) using hexane and ethyl acetate (9:1) afforded 13.2 g (75%) of ethyl (2S)-2-benzoylpropanate (22) as a yellowish liquid: 1H (CDCl3) δ1.26-1.31 (t, J=7.1 Hz, 3 H), 1.42-1.44 (d, J=6.8 Hz, 2 H), 4.01-4.12 (m, 1 H), 4.17-4.24 (q, J=7.0 Hz, 2 H), 4.42-4.46 (d, J=11.6 Hz, 1 H), 4.67-4.71 (d, J=11.6 Hz, 1 H), 7.28-7.38 (m, 5 H); 13C NMR (CDCl3) δ173.0, 137.6, 128.3, 127.8, 127.7, 74.1, 71.9, 60.6, 18.5, 14.1; IR (neat) 2985 (s), 1746 (vs), 1455 (s), 1200 (s), 1144 (vs), 698 (vs) cm-1.

Workup

  1. waitThe reaction was complete within 2 h at 25° C., during which time
  2. customa solid precipitate formed
  3. filtrationThe reaction mixture was filtered through a coarse sintered glass funnel
  4. additioncontaining Celite
  5. washThe solid was washed with diethyl ether (50 mL)
  6. washThe filtrate was washed with a saturated aqueous sodium chloride solution (3×300 mL)
  7. dry with materialdried (MgSO4)
  8. concentrationConcentration and purification by flash chromatography on silica gel (EM 60, 0.040-0.063 partical size, 230-400 Mesh, column size: 7 cm diameter×20 cm length)

Sources & evidence

ORD record
ord-a5b7bcf86e994566a3e0ba58ce07e586
Source dataset
uspto-grants-1993_05
Patent number
US05208345

Reaction notes

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