Sulfuric Acid → 2-Hydroxy-3,5-dimethyl-2-cyclopenten-1-one

HRID 2058624Notes

Reaction equation

HRID 2058624 reaction equation
[C:1]([C:4]1(C)[CH2:8][C:7]([CH3:9])=[C:6]([OH:10])[C:5]1=[O:11])(O)=O.S(=O)(=O)(O)O.[OH-].[Na+]>>[CH3:1][C:4]1[CH2:8][CH:7]([CH3:9])[C:6](=[O:10])[C:5]=1[OH:11]

Participants

4

Reactant 3

HCID 1118Sulfuric AcidHCID 14798Sodium HydroxideHCID 204720912-Carboxy-2,4-dimethylcyclopent-4-en-5-olone

Product 1

HCID 895382-Hydroxy-3,5-dimethyl-2-cyclopenten-1-oneYield 91%

Procedure

85.1 g (0.5 mol) of the acid obtained according to paragraph (c), namely 2-carboxy-2,4-dimethylcyclopent-4-en-5-olone, are treated with 851 ml of 10% sulphuric acid and the mixture is refluxed for 45 minutes. For the working-up, the mixture is adjusted to pH 7 with 2N sodium hydroxide solution and then extracted three times with methylene chloride. The combined organic phases are dried over sodium sulphate and dried in a high vacuum for 1 hour. There are obtained 57.4 g (91%) of crystalline 3,5-dimethylcyclopent-2-en-2-olone of melting point 93°-94° C. The product is identical with the product obtained according to paragraph (c) of Example 4.

Workup

  1. temperaturethe mixture is refluxed for 45 minutes
  2. extractionextracted three times with methylene chloride
  3. dry with materialThe combined organic phases are dried over sodium sulphate
  4. customdried in a high vacuum for 1 hour

Sources & evidence

ORD record
ord-6bd3aa5dbe4c4a23812408b5751ef2b1
Source dataset
uspto-grants-1982_03
Patent number
US04318855

Reaction notes

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