Hydrogenation of LSD (I) with hydrogen over palladium on carbon yields dihydrolysergic acid diethylamide (II), whereas hydrogenation of iso-LSD (III) gives a mixture of the dihydro compounds (IV) and (V).
Amidation of lysergic acid (I) using triphenyl phosphite/imidazole/phosphoric acid tris-(dimethylamide) or phosphoric acid tris-(dimethylamide)/tosyl chloride yields compounds (II) and (III). With the latter reagent, compounds (II) are obtained in 68-75% yield and compounds (III) in up to 3-8% yield.