HCID 23468761, compound → HCID 23468888, compound

HRID 128309Notes

Reaction equation

HRID 128309 reaction equation
[CH3:1][CH:2]([O:6][C:7]1[CH:17]=[CH:16][C:10]([C:11]([O:13]CC)=[O:12])=[CH:9][C:8]=1[CH3:18])[C:3](=O)[CH3:4]>S(=O)(=O)(O)O>[CH3:1][C:2]1[O:6][C:7]2[C:8]([CH3:18])=[CH:9][C:10]([C:11]([OH:13])=[O:12])=[CH:16][C:17]=2[C:3]=1[CH3:4]

Participants

3

Reactant 1

HCID 23468761HCID 23468761, compound

Product 1

HCID 23468888HCID 23468888, compound

Reagents, catalysts & solvents 1

HCID 1118Sulfuric AcidSolvent

Procedure

250.3 g (1.0 mol) of ethyl 4-(1-methyl-2-oxopropoxy)-3-methylbenzoate are stirred in 400 ml of 94% sulfuric acid, first at room temperature for 30 minutes and then at 60° for 30 minutes. The reaction mixture is cooled to room temperature, poured onto 2 kg of ice and extracted with ethyl acetate. The organic phase is washed twice with water and then extracted 3 times with 500 ml of 2 N sodium carbonate solution each time. The sodium carbonate solutions are rendered acid (pH about 2-3) with 5 N hydrochloric acid and then extracted with ethyl acetate. The organic phase is dried over magnesium sulfate and evaporated completely under a waterpump vacuum. 2,3,7-Trimethyl-5-benzofurancarboxylic acid of melting point 235°-237° is obtained from the residue by recrystallising it once from hot ethanol.

Workup

  1. extractionextracted with ethyl acetate
  2. washThe organic phase is washed twice with water
  3. extractionextracted 3 times with 500 ml of 2 N sodium carbonate solution each time
  4. extractionextracted with ethyl acetate
  5. dry with materialThe organic phase is dried over magnesium sulfate
  6. customevaporated completely under a waterpump vacuum

Sources & evidence

ORD record
ord-a7d289058c834bf2b0d1ef570236ab37
Source dataset
uspto-grants-1981_03
Patent number
US04259338

Reaction notes

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