| abstract |
The new compounds of general formula I in which A1 is a hydrogen atom, a C1-4 alkyl or C4-8 cycloalkyl group; A2 represents a C3-10 alkyl group, C3-10 alkenyl group, C4 cycloalkyl group -8, phenyl C1-4 alkyl, phenyl C2-4 alkenyl, phenyl optionally substituted by one or more C1-4 alkyl, C1-4 alkoxy or hydroxy; naphthyl; pyridyl optionally substituted with a C1-4 alkyl group; or furfuryle; and X is a valence bond or a group -CO-; provided that in the case where X is a valence bond, A2 is other than a phenyl group), have a useful effect of increasing weight gain and improving the use of food and they can be used in breeding, especially in chickens and lambs. The compounds of general formula I can be prepared according to methods known in themselves. |