Reaktion #735404

Reaktionsgleichung

Sodium metabisulphite

2-hydroxymethyl-2-methyl-2,3-dihydrobenzofuran

potassium hydroxide

Potassium permanganate

→

carboxylic acid

Ausbeute 16.9%

2-Methyl-2,3-dihydrobenzofuran-2-carboxylic acid

Ausbeute 16.9%

Lösungsmittel

water

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled to 5°
2. 2
   Temperaturmaintained below 12°
3. 3
   workup.ADDITIONAfter the addition
4. 4
   Sonstigeto destroy the precipitated MnO2
5. 5
   WaschenThe basic aqueous phase was washed with methylene chloride
6. 6
   ExtraktionExtraction with methylene chloride
7. 7
   Waschenby washing
8. 8
   Sonstigedrying
9. 9
   Sonstigeevaporation of the extracts

Vorschrift

The 2-hydroxymethyl-2-methyl-2,3-dihydrobenzofuran (16.4 g) and potassium hydroxide (5.2 g) in water (150 ml) were mixed and cooled to 5°. Potassium permanganate (20 g) was added portionwise over 45 minutes to the stirred mixture maintained below 12°. After the addition was complete stirring was continued for 1 hour and the mixture was then diluted with water. Sodium metabisulphite was added to destroy the precipitated MnO2 followed by an excess of sodium carbonate. The basic aqueous phase was washed with methylene chloride and then acidified with 2 N hydrochloric acid. Extraction with methylene chloride followed by washing, drying and evaporation of the extracts gave the carboxylic acid (3.0 g); I.R. νmax 1720 cm-1.

Quelle