6-Substituted 1-[(5R,8S,10R)-8-ergolinyl]-3,3-diethylureas II-VII were prepared from hydrazides of (5R,8S,10R)-6-alkyl-8-ergolinecarboxylic acids (VIIIa, VIIIb) via the corresponding azides IXa and IXb and isocyanates Xa and Xb, and/or from 1-[(5R,8S,10R)-6-methyl-8-ergolinyl]-3,3-diethylurea (I) via XI and XII. Two of the by-products arising in the latter route have been identified (XIII, XIV). Some of the ureas prepared, especially II and III, had strong inhibitory effects in vivo on the secretion of prolactin in rats.
6-取代的1-[(5R,8S,10R)-8-麦角酸基]-3,3-二乙基脲II-VII是通过(5R,8S,10R)-6-烷基-8-麦角酸的肼酰胺(VIIIa,VIIIb)经过相应的叠氮化物IXa和IXb和异氰酸酯Xa和Xb,或通过1-[(5R,8S,10R)-6-甲基-8-麦角酸基]-3,3-二乙基脲(I)经过XI和XII制备的。在后一种途径中产生的两种副产物已被鉴定(XIII,XIV)。其中一些制备的脲,特别是II和III,在大鼠体内对泌乳素的分泌有强烈的抑制作用。