Citric Acid → 2-(3,4-Dimethoxy-alpha-hydroxybenzyl)-3,4,5-trimethoxybenzaldehyde dimethyl acetal

HRID 974110Notes

Reaction equation

C([Li])CCC.[CH3:6][O:7][CH:8]([O:21][CH3:22])[C:9]1[CH:14]=[C:13]([O:15][CH3:16])[C:12]([O:17][CH3:18])=[C:11]([O:19][CH3:20])[CH:10]=1.[CH3:23][O:24][C:25]1[CH:26]=[C:27]([CH:30]=[CH:31][C:32]=1[O:33][CH3:34])[CH:28]=[O:29].C(O)(=O)CC(CC(O)=O)(C(O)=O)O>CCCCCC.C1C=CC=CC=1.O>[CH3:22][O:21][CH:8]([O:7][CH3:6])[C:9]1[CH:14]=[C:13]([O:15][CH3:16])[C:12]([O:17][CH3:18])=[C:11]([O:19][CH3:20])[C:10]=1[CH:28]([OH:29])[C:27]1[CH:30]=[CH:31][C:32]([O:33][CH3:34])=[C:25]([O:24][CH3:23])[CH:26]=1

Participants

Conditions

Temperature: 0 °C

Procedure

136 ml of a 1.6M n-butyl lithium solution in hexane are added to a solution of 48.5 g of 3,4,5-trimethoxybenzaldehyde dimethyl acetal in 485 ml of benzene under stirring at 0° C. for about 20 minutes. The mixture is further stirred at 0° C. for 30 minutes, and 33.2 g of 3,4-dimethoxybenzaldehyde are added thereto. After stirring the mixture at 0° to 10° C. for 2 hours, 485 ml of water and 16 g of citric acid are added thereto. After shaking the mixture, the organic layer is separated therefrom, washed with water and evaporated under reduced pressure to remove solvent. 78.5 g of 2-(3,4-dimethoxy-α-hydroxybenzyl)-3,4,5-trimethoxybenzaldehyde dimethyl acetal are thereby obtained as a yellow oil.

Workup

stirringThe mixture is further stirred at 0° C. for 30 minutes
stirringAfter stirring the mixture at 0° to 10° C. for 2 hours
stirringAfter shaking the mixture
customthe organic layer is separated
washwashed with water
customevaporated under reduced pressure
customto remove solvent

Sources & evidence

ORD record: ord-9b7874ee5c484ebca0a87ed089300ef4
Source dataset: uspto-grants-1991_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05066825

Reaction notes

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