838 mg of 3-(2-bromo-6-methyl-8alpha-ergolinyl)-1,1-diethylurea (2 mmol) is dissolved in 100 ml of dichloromethane, 1.2 g of anhydrous aluminum chloride (9 mmol) and 1.8 ml of dichloromethyl methyl ether (20 mmol) are added and stirred for 15 minutes at room temperature. The reaction mixture is mixed with ice and, after 15 minutes, with a solution of 1.5 g of tartaric acid in 50 ml of water and made alkaline with 5 ml of conc. ammonia solution. It is extracted with dichloromethane, the organic phases are dried with sodium sulfate and the solvent is distilled off. The residue is chromatographed on silica gel with dichloromethane/methanol, 406 mg (45% of theory) is isolated.
