6-Methoxy-3-(trichloromethyl)-2-benzofuran-1(3H)-one → Benzoic acid, 2-(2,2-dichloroethenyl)-5-methoxy-

HRID 2170125Notes

Reaction equation

HRID 2170125 reaction equation
[CH3:1][O:2][C:3]1[CH:11]=[C:10]2[C:6]([CH:7]([C:13](Cl)([Cl:15])[Cl:14])[O:8][C:9]2=[O:12])=[CH:5][CH:4]=1>[Zn].C(O)(=O)C>[Cl:14][C:13]([Cl:15])=[CH:7][C:6]1[CH:5]=[CH:4][C:3]([O:2][CH3:1])=[CH:11][C:10]=1[C:9]([OH:12])=[O:8]

Participants

4

Reactant 1

HCID 1578786-Methoxy-3-(trichloromethyl)-2-benzofuran-1(3H)-one

Product 1

HCID 11543295Benzoic acid, 2-(2,2-dichloroethenyl)-5-methoxy-Yield 64.4%

Reagents, catalysts & solvents 2

HCID 23994ZincCatalystHCID 176Acetic AcidSolvent

Procedure

A 100 mL round-bottomed flask containing a stirring bar was charged with 6-methoxy-3-(trichloromethyl)isobenzofuran-1(3H)-one (3.09 g, 10.94 mmol) and glacial acetic acid (40.0 mL). Zinc dust (2.86 g, 43.76 mmol) was added in small portions over 30 min. to the stirred reaction mixture. The reaction was left stirring at room temperature for further 30 min. and then heated at reflux for 1 h. It was filtered hot over a pad of Celite and the filtrates were diluted with water. The precipitate formed was collected by filtration and recrystallised from EtOH/H2O to give 2-(2,2-dichlorovinyl)-5-methoxybenzoic acid as white needles (1.74 g, 64%). Spectral data for this compound were consistent with those in the literature. M.p. 164-166° C. (lit. m.p. 167-168° C.); 1H NMR (400 MHz, DMSO-d6): δ=13.31 (br. s, 1H), 7.51 (d, J=8.7 Hz, 1H), 7.47-7.39 (m, 2H), 7.21 (dd, J=8.7 Hz, J=2.2 Hz, 1H), 3.82 (s, 3H).

Workup

  1. additionA 100 mL round-bottomed flask containing a stirring bar
  2. waitThe reaction was left
  3. temperatureheated
  4. temperatureat reflux for 1 h
  5. filtrationIt was filtered hot over a pad of Celite
  6. additionthe filtrates were diluted with water
  7. customThe precipitate formed
  8. filtrationwas collected by filtration
  9. customrecrystallised from EtOH/H2O

Sources & evidence

ORD record
ord-d13c5a19b7eb4571b1b17d25dacde0e4
Source dataset
uspto-grants-2015_06
Patent number
US09050586B2

Reaction notes

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