3-(2,5-Dimethoxyphenyl)-2-propenoic acid → 2,5-Dimethoxyhydrocinnamic acid

HRID 1534135Notes

Reaction equation

HRID 1534135 reaction equation
COC(C1C=CC=CC=1)=C(OC)C(O)=O.[CH3:16][O:17][C:18]1[CH:28]=[CH:27][C:26]([O:29][CH3:30])=[CH:25][C:19]=1[CH:20]=[CH:21][C:22]([OH:24])=[O:23].[H][H]>[Pd].C(O)C>[CH3:16][O:17][C:18]1[CH:28]=[CH:27][C:26]([O:29][CH3:30])=[CH:25][C:19]=1[CH2:20][CH2:21][C:22]([OH:24])=[O:23]

Participants

6

Reactant 3

HCID 1145783-(2,5-Dimethoxyphenyl)-2-propenoic acidHCID 53756415HCID 53756415, compoundHCID 178418361HCID 178418361, compound

Product 1

HCID 663432,5-Dimethoxyhydrocinnamic acidYield 405.1%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

Polymer VIII was prepared by reacting PEI with a lactone derivative of dimethoxycinnamic acid as described by Taylor (1962). The lactone was prepared using known procedures (Anliker et al. 1957; Westfahl et al. 1954; Fichter et al. 1927). 2,5-dimethoxycinnamic acid (Aldrich Chemical Company, 2.73 g, 3.1 mmole) was added to a mixture of 10% palladium on carbon catalyst (Aldrich Chemical Company, 0.54 g) in 100 mL 95% ethanol under 34 psi hydrogen gas. The mixture was shaken for 4 hours, converting the double bond into a single bond with saturated carbons. The catalyst was filtered off and the filtrate was evaporated to dryness to give 2.64 g of 2,5-dimethoxyhydrocinnamic acid (95% yield). This intermediate (2.20 g, 10.5 mmole) was refluxed in 48% aqueous HBr (15 mL, 132 mmole) for 2.5 hours. As the solution was cooled, white crystals appeared. The mixture was cooled further to 2° C., then the crystals were filtered off, washed with cold water, and dried in vacuo, yielding 1.40 g (81%), melting point 160°-161° C. (reported mp 162°-163° C.). 1H-NMR in D6-acetone confirmed the structure. IR spectra (KBr pellets) showed the lactone band at 1736 cm-1.

Workup

  1. customPolymer VIII was prepared
  2. filtrationThe catalyst was filtered off
  3. customthe filtrate was evaporated to dryness

Sources & evidence

ORD record
ord-7d992b77c731498aa89b2c2e9aad9394
Source dataset
uspto-grants-1992_02
Patent number
US05087671

Reaction notes

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