Dimethylformamide → 1-(1-Ethylpropyl)-6-methylergoline-8carboxylic acid

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Reaction Steps

A 250 ml, three-neck round bottom flask was charged with 10.0 g (33.9 mmol) of 92% pure 9,10-dihydrolysergic acid, 10.3 g (158 mmol) of 86% pure powdered potassium hydroxide and 75 ml of DMF. The mixture was stirred until the solid constituents were completely dissolved, and 17.9 g (73.9 mmol) of p-toluenesulfonic acid, 1-ethylpropyl ester was added. The reaction mixture was stirred at room temperature overnight and 300 ml of deionized water was added. The mixture was filtered, and 1N hydrochloric acid was added to the filtrate until the pH was adjusted to approximately 6.5. The precipitated solid was collected by vacuum filtration and rinsed with water to provide 6.9 g of 1-(1-ethylpropyl)-6-methylergoline-8-carboxylic acid. The identity of the solid was determined by thin layer chromatography employing chloroform:methanol:acetic acid (18:6:1, v:v:v) as the solvent system as compared to an authentic reference standard. The products obtained from Example 1 and Example 2 were combined to provide 7.6 g of solid, which was recrystallized from methanol to provide 2.1 g of the desired product following drying of the solid in vacuo. The purity of the product was 95.6% as determined by HPLC as compared to an authentic reference standard.

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