(3,4-Dimethoxyphenyl)acetic acid → 3-Methylveratrole

HRID 1605196Notes

Reaction equation

HRID 1605196 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5](C)[CH:6]=[CH:7][C:8]=1[O:9][CH3:10].[Al+3].[Cl-].[Cl-].[Cl-].[CH3:16]OC1C=C(CC(Cl)=O)C=CC=1OC.COC1C=C(CC(O)=O)C=CC=1OC>C(=S)=S>[CH3:10][O:9][C:8]1[C:3]([O:2][CH3:1])=[C:4]([CH3:16])[CH:5]=[CH:6][CH:7]=1

Participants

6

Reactant 4

HCID 7139(3,4-Dimethoxyphenyl)acetic acidHCID 681263,4-DimethoxytolueneHCID 3604458(3,4-Dimethoxyphenyl)acetyl chlorideHCID 6451240Aluminum(III) Chloride

Product 1

HCID 782153-MethylveratroleYield 80%

Reagents, catalysts & solvents 1

HCID 6348Carbon DisulfideSolvent

Procedure

To a stirred solution of 35.6 g (0.24 mole) of 3,4-dimethoxytoluene and 14.6 g (0.11 mole) AlCl3 in 200 ml CS2 there was added dropwise over the course of 1 hr. 0.1 mole 3,4-dimethoxyphenylacetyl chloride (freshly prepared from 3,4-dimethoxyphenylacetic acid). The mixture was stirred overnight at 25°, poured into ice, and the resulting oil extracted into benzene. The extracts were dried and evaporated to yield a black viscous oil from which excess dimethoxytoluene was distilled in vacuo. After the pot residue had cooled, alcohol was added and the mixture was allowed to stand 24 hr at 0°. This allowed isolation of essentially pure ketone 4,5-dimethoxy-2-(3,4-dimethoxyphenylacetyl) toluene as a brown powder (25.4 g or 80% yield based upon the acid chloride). An analytical sample was recrystallized from EtOH-EtOAc to yield 4,5-dimethoxy-2-(3,4-dimethoxyphenylacetyl) toluene as white needles, mp 115°. Nmr (δ): 2.52 (s, 3H), 3.82 (s, 6H), 3.85 (s, 3H), 3.88 (s, 3H), 4.15 (s, 2H), 6.68 (s, 1H), 6.77 (s, 3H), 7.30 (s, 1H). Anal. Calcd for C19H22O5 : C, 69.07; H, 6.71. Found: C, 68.84; H, 6.93.

Workup

  1. additionpoured into ice
  2. extractionthe resulting oil extracted into benzene
  3. customThe extracts were dried
  4. customevaporated

Sources & evidence

ORD record
ord-2a503f5936d34432a8e7acfdcdac05ad
Source dataset
uspto-grants-1976_04
Patent number
US03950236

Reaction notes

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