Hexamethylphosphoramide → Dibenzyl 2-methylenepentanedioate

HRID 989622Notes

Reaction equation

HRID 989622 reaction equation
[C:1]([O:5][CH2:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)(=[O:4])[CH:2]=[CH2:3].CN(P(N(C)C)(N(C)C)=O)C>>[CH2:3]=[C:2]([CH2:3][CH2:2][C:1]([O:5][CH2:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)=[O:4])[C:1]([O:5][CH2:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][CH:8]=1)=[O:4]

Participants

3

Reactant 2

HCID 12679HexamethylphosphoramideHCID 75617Benzyl acrylate

Product 1

HCID 10947302Dibenzyl 2-methylenepentanedioateYield 92.5%

Procedure

Benzyl acrylate (500 g, 3.0 mol) was heated in an oil bath to 1000° C. Heating was stopped and HMPT (10 g, 61 mmol) was added dropwise while maintaining an internal temperature below 140° C. Once addition was complete, the mixture was stirred and cooled to room temperature. A slurry of silica (5:1 Hexane/EtOAc) was added and the mixture was placed in a column containing a plug of dry silica. The column was washed with 1:1 Hexane/EtOAc and the fractions were combined and evaporated to give 450 g of clear light golden liquid. The liquid was distilled under high vacuum (200 μHg) at 185° C. to give 212 g (42%) of a clear and colorless liquid. 1H NMR (CDCl3): 7.3 ppm (m, 10H), 6.2 ppm (s, 1H), 5.6 ppm (s, 1H), 5.2 ppm (s, 2H), 5.1 ppm (s, 2H), 2.6 ppm (m, 4H).

Workup

  1. temperatureHeating
  2. temperaturewhile maintaining an internal temperature below 140° C
  3. additionOnce addition
  4. additionA slurry of silica (5:1 Hexane/EtOAc) was added
  5. additioncontaining a plug of dry silica
  6. washThe column was washed with 1:1 Hexane/EtOAc
  7. customevaporated

Sources & evidence

ORD record
ord-9bcc6041784e4f8aab7bd542be579185
Source dataset
uspto-grants-2002_10
Patent number
US06458775B1

Reaction notes

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