Peptides as oxytocin agonists

A compound of formula

• wherein
• R1 is methyl or cyclopropyl;
• R2 is hydrogen;
• R3 is hydrogen, lower alkyl, lower alkyl substituted by hydroxy, —(CH2)2C(O)NH2, benzyl, phenyl, —CH2-five membered aromatic heterocyclic group, CH2-indolyl, —CH2-cycloalkyl, cycloalkyl or —(CH2)2—S-lower alkyl;
• R3′ is hydrogen or lower alkyl;
• or
• X is —C(O)—CHR4—CHR4′—C(O)—NH—CH2—
• R4/R4′ are hydrogen or one of R4 or R4′ is amino:
• o is 0 or 1;
• or a pharmaceutically acceptable acid addition salt, a racemic mixture or its corresponding enantiomer and/or optical isomers thereof.