Potassium Hydroxide → 1-(1-Ethylpropyl)-6-methylergoline-8carboxylic acid

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Reaction Steps

A 500 ml, three-neck round bottom flask was charged with 11.72 g (180.0 mmol) of 86% pure powdered potassium hydroxide, 10.0 g (33.9 mmol) of 92% pure 9,10-dihydrolysergic acid and 150 ml of DMSO. The mixture was stirred at room temperature for 15 minutes, and 10.3 g (42.6 mmol) of p-toluenesulfonic acid, 1-ethylpropyl ester was added. The mixture was stirred at room temperature for 19 hours, and 1000 ml of ice water was added. The mixture was washed twice with 250 ml aliquots of ethyl acetate, and the pH of the aqueous layer was adjusted to 5 with glacial acetic acid. The mixture was cooled and the precipitated solid was collected by vacuum filtration. The solid was dried under vacuum to provide 7.94 g of 1-(1-ethylpropyl)-6-methylergoline-8carboxylic acid. A second crop of material was obtained to provide 0.9 g of product. The purity of the first crop was 96.7%, and the purity of the second crop was 96%. Total yield 72.1%. The identity of the product was determined by thin layer chromatography as compared to an authentic reference standard.

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