Patent ID: 7423152

Claim:
A process for the manufacture of the compound of formula (1): comprising: a) reacting a compound of formula (I): with an amine of formula HNR 2 R 3 to obtain a compound of formula (II): b) further reacting a compound of formula (II) with an ethyl-base to obtain a compound of formula (III): c) further reacting said compound of formula (III) with a compound of formula (IV): to obtain a compound of formula (V): d) further reacting said compound of formula (V) with ozone to obtain a compound of formula (VI): e) further reacting said compound of formula (VI) with a compound of formula (VII): and a base, to obtain a compound of formula (VIII): f) further reacting said compound of formula (VIII) with di(C 1 -C 6 )-alkylformamide, di(C 1 -C 6 )-alkylacetal or a compound of the formula (R 7 R 8 N) 3 —CH to obtain a compound of formula (IX): g) further reacting said compound of formula (IX) with ammonium acetate to obtain a compound of formula (X): h) further reacting said compound of formula (X) with alkali metal borohydrides and earth metal salts to obtain a compound of formula (XI): i) further reacting said compound of formula (XI) with concentrated mineral acids to obtain the compound of formula (1); wherein: R, R 1 , R 7 and R 8 independently from each other are (C 1 -C 6 )-alkyl; R 2 , R 3 and R 4 independently from each other are selected from the group consisting of (C 1 -C 6 )-alkyl and (C 3 -C 7 )-cycloalkyl; and R 5 and R 6 independently from each other are selected from the group consisting of (C 1 -C 6 )-alkyl and an aryl group.