Hydrochloric Acid → 5,6-Dimethoxy-3H-isobenzofuran-1-one

HRID 2300047Notes

Reaction equation

HRID 2300047 reaction equation
[CH3:1][O:2][C:3]1[CH:4]=[C:5]([CH:9]=[CH:10][C:11]=1[O:12][CH3:13])[C:6]([OH:8])=[O:7].[CH2:14]=O.Cl>>[CH3:13][O:12][C:11]1[CH:10]=[C:9]2[C:5](=[CH:4][C:3]=1[O:2][CH3:1])[C:6](=[O:8])[O:7][CH2:14]2

Participants

4

Reactant 3

HCID 313Hydrochloric Acid2×HCID 712FormaldehydeHCID 7121Veratric Acid

Product 1

HCID 2304605,6-Dimethoxy-3H-isobenzofuran-1-oneYield 58.65%

Conditions

Temperature
60 °C

Procedure

A suspension of 3,4-dimethoxy-benzoic acid (353.5 g, 1.94 moles) in HCHO (1.7 l, 24.5 moles) under stirring was prepared and cooled in ice, saturated with gaseous HCl (340 g, 9.32 moles), then gradually warmed to 60° C. After one night the temperature was cooled to the room value and further HCl (300 g) was bubbled in, then the temperature was brought again to 60° C. for one night. The mixture was partially evaporated, taken up in water (1 l), neutralised with 28% NH4OH (1.5 l) and kept at cold for 2 hours, then filtered. The filtrate was washed with water up to neutrality, then crystallised from methanol (2 l) and dried under vacuum at 60° C. to give 220 g of the title compound (yield: 58.65%).

Workup

  1. customwas prepared
  2. customwas bubbled in, then the temperature
  3. waitwas brought again to 60° C. for one night
  4. customThe mixture was partially evaporated
  5. customcold for 2 hours
  6. filtrationfiltered
  7. washThe filtrate was washed with water up to neutrality
  8. customcrystallised from methanol (2 l)
  9. customdried under vacuum at 60° C.

Sources & evidence

ORD record
ord-d69e3b09a43e408db596f2eed3373f84
Source dataset
uspto-grants-2002_12
Patent number
US06498160B2

Reaction notes

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