3-Methyl-2-buten-1-OL → Methyl 3,3-dimethyl-4-pentenoate

HRID 1758563Notes

Reaction equation

HRID 1758563 reaction equation
[C:1](OC)([O:5][CH3:6])([O:3]C)[CH3:2].[CH3:9][C:10]([CH3:14])=[CH:11][CH2:12]O>P(=O)(O)(O)O.CO>[CH3:9][C:10]([CH3:14])([CH:11]=[CH2:12])[CH2:2][C:1]([O:5][CH3:6])=[O:3]

Participants

5

Reactant 2

HCID 111733-Methyl-2-buten-1-OLHCID 15050Trimethyl orthoacetate2×

Product 1

HCID 114129Methyl 3,3-dimethyl-4-pentenoateYield 82.8%

Reagents, catalysts & solvents 2

HCID 1004Phosphoric AcidCatalystHCID 887MethanolSolvent

Conditions

Temperature
110 °C

Procedure

A mixture of trimethyl orthoacetate (120 g; 1 mole) and orthophosphoric acid (1.5 g; 0.015 mole) was placed in a flask equipped with a stirrer and a vacuum-jacketed fractionating column and the mixture was heated, with stirring to a temperature of 110° C. 3-Methylbut-2-enol (21.5 g; 0.25 mole) was added dropwise to the hot reaction mixture over a period of 1 hour during which time the methanol formed was collected by distillation. On completion of the addition the reaction mixture was heated at a temperature of 110° C. for a further period of 1 hour with collection of methanol by distillation. Portion (72 g; 0.6 mole) of the excess trimethyl orthoacetate was then distilled from the reaction mixture, the distillation being continued until the reaction mixture reached a temperature of 140°-145° C. The reaction mixture was then heated to a temperature of 140°-145° C. for a period of 1.5 hours, the remaining excess trimethyl orthoacetate being allowed to condense and return to the reaction mixture. The product was then distilled to separate the remaining excess trimethyl orthoacetate and to give methyl 3,3-dimethylpent-4-enoate (29.4 g; 82.8%), bp 70° C. at 60 mm Hg.

Workup

  1. customwas placed in a flask
  2. customequipped with a stirrer
  3. temperaturea vacuum-jacketed fractionating column and the mixture was heated
  4. customformed
  5. distillationwas collected by distillation
  6. additionOn completion of the addition the reaction mixture
  7. temperaturewas heated at a temperature of 110° C. for a further period of 1 hour with collection of methanol by distillation
  8. distillationthe distillation
  9. customa temperature of 140°-145° C
  10. temperatureThe reaction mixture was then heated to a temperature of 140°-145° C. for a period of 1.5 hours
  11. customthe remaining excess trimethyl orthoacetate being allowed to condense
  12. distillationThe product was then distilled
  13. customto separate the remaining excess trimethyl orthoacetate

Sources & evidence

ORD record
ord-686777765dcc4230bfa1e0087d4b30bd
Source dataset
uspto-grants-1983_02
Patent number
US04374264

Reaction notes

Loading…