Methanol → HCID 21946122, compound

HRID 1819831Notes

Reaction equation

HRID 1819831 reaction equation
[CH2:1]=[C:2]1O[C:4](=[O:5])[CH2:3]1.[Cl:7][C:8]1[C:9]([OH:21])=[C:10]([CH2:15][CH2:16][C:17]([O:19][CH3:20])=[O:18])[CH:11]=[CH:12][C:13]=1[OH:14].CO>CS(O)(=O)=O>[Cl:7][C:8]1[C:9]([OH:21])=[C:10]([CH2:15][CH2:16][C:17]([O:19][CH3:20])=[O:18])[CH:11]=[C:12]2[C:13]=1[O:14][C:4](=[O:5])[CH:3]=[C:2]2[CH3:1]

Participants

5

Reactant 3

HCID 887MethanolHCID 12661DiketeneHCID 21946098Methyl 3-(3-chloro-2,4-dihydroxyphenyl)propanoate

Product 1

HCID 21946122HCID 21946122, compoundYield 64.3%

Reagents, catalysts & solvents 1

HCID 6395Methanesulfonic AcidSolvent

Procedure

Diketene (0.7 ml, 9.1 mmol) was added dropwise to a stirred solution of 5a (1.0 g, 4.3 mmol) in 7 ml of methanesulfonic acid. The resultant solution was heated at 70° C. for 5 min and cooled. Methanol (20 ml) was added and the reaction was heated to boiling; this treatment esterified small amount of free acid formed during the cyclization step. Methanol was evaporated and water was added to precipitate the product. The crude material was chromatographed on silica eluting with ethyl acetate. Concentration of the pure product fractions and drying under vacuum afforded 0.82 g (64%) of the desired product as a pale yellow solid. 1H NMR (DMSO-d6): δ 10.45 (s, 1H), 7.50 (s, 1H), 6.24 (s, 1H), 3.59 (s, 3H), 2.93 (t, J=7.5 Hz, 2H), 2.62 (t, J=7.5 Hz, 2H), 2.38 (s, 3H).

Workup

  1. temperaturecooled
  2. temperaturethe reaction was heated to boiling
  3. customformed during the cyclization step
  4. customMethanol was evaporated
  5. additionwater was added
  6. customto precipitate the product
  7. customThe crude material was chromatographed on silica eluting with ethyl acetate
  8. customConcentration of the pure product fractions and drying under vacuum

Sources & evidence

ORD record
ord-c12cce9c47084fc48aa58b7f7c9c48f4
Source dataset
uspto-grants-2009_10
Patent number
US07601851B2

Reaction notes

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