Benzyl Bromide → Benzyl 4-pentynoate

HRID 1725997Notes

Reaction equation

HRID 1725997 reaction equation
[C:1]([OH:7])(=[O:6])[CH2:2][CH2:3][C:4]#[CH:5].C([O-])([O-])=O.[K+].[K+].[CH2:14](Br)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1>CN(C=O)C.O>[C:1]([O:7][CH2:14][C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1)(=[O:6])[CH2:2][CH2:3][C:4]#[CH:5]

Participants

6

Reactant 3

HCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 224644-Pentynoic acid

Product 1

HCID 561097Benzyl 4-pentynoateYield 100%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6228DimethylformamideSolvent

Procedure

A solution of 4-pentynoic acid (5.25 g, 53.5 mmol) in DMF (107 mL) was treated with K2CO3 (11.09 g, 80.3 mmol) and benzyl bromide (6.37 mL, 53.5 mmol), stirred for 24 hours, diluted with water (200 mL), and extracted with diethyl ether (3×150 mL). The combined organic extracts were dried (MgSO4), filtered, and concentrated. The residue was purified by flash chromatography to provide the desired product (10.07 g, 100%). MS (ESI(+)) m/e 206 (M+NH4)+; 1H NMR (300 MHz, DMSO-d6) δ 7.37 (m, 5H), 5.12 (s, 2H), 2.61 (t, 1H), 2.57 (m, 2H), 2.42 (m, 2H).

Workup

  1. extractionextracted with diethyl ether (3×150 mL)
  2. dry with materialThe combined organic extracts were dried (MgSO4)
  3. filtrationfiltered
  4. concentrationconcentrated
  5. customThe residue was purified by flash chromatography

Sources & evidence

ORD record
ord-b4693974fceb44688bed847758edd695
Source dataset
uspto-grants-2009_02
Patent number
US07491718B2

Reaction notes

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