Hydrochloric Acid → (E)-3,4-Dimethoxycinnamic acid

HRID 1616737Notes

Reaction equation

HRID 1616737 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:8]=[CH:9][C:10]=1[O:11][CH3:12])[CH:6]=O.C(O)(=O)[CH2:14][C:15]([OH:17])=[O:16].Cl>N1CCCCC1.N1C=CC=CC=1>[CH3:1][O:2][C:3]1[CH:4]=[C:5](/[CH:6]=[CH:14]/[C:15]([OH:17])=[O:16])[CH:8]=[CH:9][C:10]=1[O:11][CH3:12]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 867Malonic AcidHCID 8419Veratraldehyde

Product 1

HCID 717531(E)-3,4-Dimethoxycinnamic acidYield 81.6%

Reagents, catalysts & solvents 2

HCID 1049PyridineSolventHCID 8082PiperidineSolvent

Conditions

Temperature
120 °C

Procedure

A solution of 3,4-dimethoxybenzaldehyde (5.0 g, 30 mmol) and malonic acid (4.7 g, 45 mmol) in a mixture of piperidine (0.5 mL) and pyridine (15 mL) was heated to 120° C. and stirred overnight. The mixture was cooled to rt and acidified with conc. HCl. The resulting precipitate was filtered and washed with water to give (E)-3-(3,4-dimethoxyphenyl)-2-propenoic acid (5.1 g, 81%) as a pale brown solid; δH (400 MHz, DMSO-d6) 3.78 (s, 3H, OCH3), 3.79 (s, 3H, OCH3), 6.42 (d, J=16.0 Hz, 1H, CH═CHCO2H), 6.96 (d, J5,6=8.0 Hz, 1H, H5), 7.19 (d, J5,6=8.0 Hz, 1H, H6), 7.30 (s, 1H, H2), 7.51 (d, J=16.0 Hz, 1H, CH═CHCO2H).

Workup

  1. temperatureThe mixture was cooled to rt
  2. filtrationThe resulting precipitate was filtered
  3. washwashed with water

Sources & evidence

ORD record
ord-c4a8d0c14039491e84a31460651a3951
Source dataset
uspto-grants-2014_07
Patent number
US08765812B2

Reaction notes

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