The present invention relates to a process for the manufacture of compounds of formula wherein the substituents are as described herein which comprises the steps of a) reacting a compound of formula with a compound of formula to form a compound of formula b) converting the OH/═O function of compounds of formula XIV/XIVa into a leaving group P with a reagent containing a leaving group, selected from POCl3, PBr3, MeI and (F3CSO2)2O to form a compound of formula wherein P is halogen or trifluoromethanesulfonate; c) substituting R2 for the leaving group P by reacting compound XV with HR2 to form a compound of formula and d) hydrolyzing the nitrile function in an acidic medium selected from H2SO4, HCl and acetic acid, to form a compound of formula I The compounds of formula I are valuable intermediates for the manufacture of therapeutically active compounds which have NK-1 antagonist activity.