Ammonia → 3-(9,10-Didehydro-2,3-dihydro-6-methyl-8alpha-ergolinyl)-1,1-diethylurea

Beteiligte Stoffe

Reaktionsschritte

At -20° C., 19.6 g of 3-(9,10-didehydro-6-methyl-8α-ergolinyl)-1,1-diethylurea is dissolved in 80 ml of trifluoroacetic acid, and 8 portions of respectively 500 mg of sodium borohydride are added at intervals of 3-4 minutes. The mixture is then poured on ice, made alkaline under ice cooling with 90 ml of 26% ammonia solution, and extracted with methylene chloride. The organic phase is dried, concentrated, and chromatographed on silica gel with methylene chloride/methanol, thus isolating 10.6 g of 3-(9,10-didehydro-2,3-dihydro-6-methyl-8α-ergolinyl)-1,1-diethylurea as a mixture of isomers of the 3α and 3β-H-compounds. Crystallization from ethyl acetate yields 6.5 g of the 3β-H-compound.

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