Allyl bromide → 2-Formyl-3-hydroxy-5-methoxy-6-methylbenzoic acid allyl ester

HRID 1377842

Reaction equation

HRID 1377842 reaction equation
[OH:1][CH:2]1[C:10]2[C:5](=[C:6]([CH3:14])[C:7]([O:12][CH3:13])=[CH:8][C:9]=2[OH:11])[C:4](=[O:15])[O:3]1.CN(C)C(N(C)C)=N.[CH2:24](Br)[CH:25]=[CH2:26]>CN(C)C=O>[CH2:26]([O:3][C:4](=[O:15])[C:5]1[C:6]([CH3:14])=[C:7]([O:12][CH3:13])[CH:8]=[C:9]([OH:11])[C:10]=1[CH:2]=[O:1])[CH:25]=[CH2:24]

Participants

5

Reactant 3

HCID 7841Allyl bromideHCID 664601,1,3,3-TetramethylguanidineHCID 11160120HCID 11160120, compound

Product 1

HCID 537352632-Formyl-3-hydroxy-5-methoxy-6-methylbenzoic acid allyl esterYield 74.6%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

To a solution of 42.0 g of (RS)-3,4-dihydroxy-6-methoxy-7-methyl-1,3-dihydro-isobenzofuran-1-one in 1 l of N,N-dimethylformamide were added 23.0 g of 1,1,3,3-tetramethylguanidine. The solution was stirred for 30 min and then, 48.4 g of allyl bromide were added and stirring was continued for 3 h. The mixture was evaporated in vacuo and the residue was dissolved in 0.7 l of ethyl acetate. The solution was washed with brine, dried over sodium sulfate, and the .solvent was evaporated in vacuo. The solid residue was crystallized from tert-butyl methyl ether to give 37.3 g of 2-formyl-3-hydroxy-5-methoxy-6-methylbenzoic acid allyl ester as white crystals of m.p. 73°-74° C.

Workup

  1. stirringstirring
  2. waitwas continued for 3 h
  3. customThe mixture was evaporated in vacuo
  4. dissolutionthe residue was dissolved in 0.7 l of ethyl acetate
  5. washThe solution was washed with brine
  6. dry with materialdried over sodium sulfate
  7. customthe .solvent was evaporated in vacuo
  8. customThe solid residue was crystallized from tert-butyl methyl ether

Sources & evidence

ORD record
ord-c75c4ca8b22f46079ae03b073a120c1b
Source dataset
uspto-grants-1997_09
Patent number
US05665746

Linked notes

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