Growth hormone secretagogues

Compounds of the formula I

• 10
• wherein * means a carbon atom which, when a chiral carbon atom, has a R or S configuration, one of R1 and R3 is an hydrogen atom and the other is a group of formula II
• 11
• R2 is a hydrogen atom, a linear or branched C1-C6 alkyl group, an aryl group, a heterocyclic group, a cycloalkyl group, a (CH2)n-aryl group, a (CH2)n-heterocyclic group, a (CH2)n-cycloalkly group, a methylsulfonyl group, a phenylsulfonyl group, a C(O)R8 group or a group according to one of formulas III to VIII:
• 12
• 13
• R4 is a hydrogen atom or a linear or branched C1-C4-alkyl group, R5 is a hydrogen atom, a linear or branched C1-C4 alkyl group, a (CH2)n-aryl group, a (CH2)n-heterocyclic group, a (CH2)n-cycloalkyl group or an amino group, R6 and R7 are independently from each other a hydrogen atom or a linear or branched C1-C4-alkyl group, R8 is a linear or branched C1-C6-alkyl group, R9, R10, R11, R12, R13, R14, R15, and R16 are independently from each other a hydrogen atom or a linear or branched C1-C4-alkyl group, m is 0, 1 or 2 and n is 1 or 2.