Sodium Hydroxide → 2-Ethylazulene

Participants

Reaction Conditions

Reaction Steps

3.7 g (16.4 mmol) of the above-obtained 1-cyano-2-ethylazulene-3-carboxylic acid was separated into two parts, i.e., about 1 g and a remaining part. 30 ml of 75% sulfuric acid was added to the first part, i.e., about 1 g of 1-cyano-2-ethylazulene-3-carboxylic acid and heated to 90° C., and thereafter gradually supplied with the remaining part of 1-cyano-2-ethylazulene-3-carboxylic acid. The mixture was heated at 90° C. for 2 hours and further at 120° C. for 2 hours. The obtained reaction solution was added to an aqueous solution containing 35 g of sodium hydroxide and extracted with a mixed solution of hexane and ethyl acetate. An organic phase of the extract was removed under a reduced pressure. The resultant crude product was purified by silica gel column chromatography, to obtain 1.71 g of 2-ethyl azulene (yield: 67%).

Provenance & Evidence