Benzene → 1-Methylethyl (2E)-2-butenoate

HRID 2414859Notes

Reaction equation

HRID 2414859 reaction equation
[C:1]([OH:6])(=[O:5])/[CH:2]=[CH:3]/[CH3:4].[CH:7](O)([CH3:9])[CH3:8].C1C=CC=CC=1.OS(O)(=O)=O>C1(C)C=CC(S(O)(=O)=O)=CC=1.CCOCC.O>[CH:7]([O:5][C:1](=[O:6])/[CH:2]=[CH:3]/[CH3:4])([CH3:9])[CH3:8]

Participants

8

Reactant 4

HCID 241BenzeneHCID 1118Sulfuric AcidHCID 3776IsopropanolHCID 637090Crotonic Acid

Product 1

HCID 53543591-Methylethyl (2E)-2-butenoateYield 57%

Reagents, catalysts & solvents 3

HCID 6101p-Toluenesulfonic acidCatalystHCID 962WaterSolvent2×HCID 3283Diethyl EtherSolvent

Procedure

40.0 g (465 mmol) of crotonic acid (Fluka 28010), 25.1 g (418 mmol) of isopropanol (Merck 1.09634.2500), 200 mL of benzene, 4.2 g of conc. H2SO4 and 2.1 g of para-toluene sulfonic acid was charged to a 500 mL flask equipped with a magnetic stirrer bar and Dean-Stark water separator. The mixture was refluxed until water formation ceased. 200 mL of ether was added to the mixture, and then washed with several portions of NaHCO3 (aq., sat.) until the the acid was neutralized. Organic phase was separated, dried with MgSO4 and filtered. Solvent was removed under reduced pressure and the remainder distilled at 95° C. to give 30.5 g of isopropylcrotonate. Yield 57%. 1H-NMR (CDCl3): 6.95 (dq, 1H), 5.82 (d, 1H), 5.05 (sept, 1H), 1.88 (d, 3H), 1.25 (d, 6H).

Workup

  1. customequipped with a magnetic stirrer bar
  2. washwashed with several portions of NaHCO3 (aq., sat.) until the the acid
  3. customOrganic phase was separated
  4. dry with materialdried with MgSO4
  5. filtrationfiltered
  6. customSolvent was removed under reduced pressure
  7. distillationthe remainder distilled at 95° C.

Sources & evidence

ORD record
ord-05d44817db064cdea8f7bb756aa90ac1
Source dataset
uspto-grants-2004_11
Patent number
US06815514B2

Reaction notes

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