Hexamethylphosphorous triamide → Di-tert-butyl 2-methylenepentanedioate

HRID 1976708Notes

Reaction equation

HRID 1976708 reaction equation
[C:1]([O:5][C:6]([CH3:9])([CH3:8])[CH3:7])(=[O:4])[CH:2]=[CH2:3].CN(C)P(N(C)C)N(C)C>>[CH2:3]=[C:2]([CH2:3][CH2:2][C:1]([O:5][C:6]([CH3:9])([CH3:8])[CH3:7])=[O:4])[C:1]([O:5][C:6]([CH3:9])([CH3:8])[CH3:7])=[O:4]

Participants

3

Reactant 2

HCID 15355Hexamethylphosphorous triamideHCID 15458tert-Butyl acrylate

Product 1

HCID 11054274Di-tert-butyl 2-methylenepentanedioate

Conditions

Temperature
100 °C

Procedure

Tert-butyl acrylate (465 g, 3.628 mol) was warmed to 100° C. under nitrogen, then hexamethylphosphorous triamide (10 g, 61.2 mmol) was added dropwise and the addition rate was adjusted to maintain the reaction temperature at 100° C. The reaction mixture was allowed to cool, then poured over a plug of silica (˜1000 ml) and washed completely off the silica with 4:1 hexane/ethyl acetate. The solvent was removed under reduced pressure and the resulting oil was distilled. Some material was collected from room temperature to 50° C. under high vacuum, and discarded. The temperature was then raised to ˜80° C. and the product (300 g, 65%, b.p. 67-70° C. at 300 μ) was collected as a clear oil. 1H NMR (CDCl3): δ 1.4 (m, 18H), 2.4 (t, 2H), 2.6 (t, 2H), 5.5 (s, 1H), 6.0 (s, 1H).

Workup

  1. temperatureto cool
  2. additionpoured over a plug of silica (˜1000 ml)
  3. washwashed completely off the silica with 4:1 hexane/ethyl acetate
  4. customThe solvent was removed under reduced pressure
  5. distillationthe resulting oil was distilled
  6. customSome material was collected from room temperature to 50° C. under high vacuum
  7. temperatureThe temperature was then raised to ˜80° C.
  8. customthe product (300 g, 65%, b.p. 67-70° C. at 300 μ) was collected as a clear oil

Sources & evidence

ORD record
ord-516a40776883445e90e63a642c11d42b
Source dataset
uspto-grants-2001_05
Patent number
US06228888B1

Reaction notes

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