Patent ID: 7705155

Claim:
A process for the production of compounds of formula (I) and pharmaceutically acceptable salts and esters thereof, comprising a) reacting a compound of formula (II), with a compound of formula (III), and b) further reacting in the presence of alkali- or earth alkali metal hydroxides to give the compounds of formula (I), wherein R and R 1 are independently, alkyl or benzyl, which benzyl is optionally substituted by one, two or three substituents including —O-alkyl; alkyl or halogen; with the proviso that: if R is alkyl, R 1 in formula (I) may also be hydrogen or silyl, and R 1 in formula (II) may also be silyl; R 2 is hydrogen or halogen; X is R 3 and R 4 are hydrogen, phenyl, alkyl or —C(CH 3 ) 2 -phenyl; R 5 is phenyl, benzyl or alkyl; R 6 is hydrogen, alkyl or phenyl; and R 7 is hydrogen, methyl or phenyl; or alternatively R 5 and R 6 , together with the carbon atoms to which they are attached form an indan moiety and R 7 is hydrogen; R 11 and R 12 air independently alkyl, cycloalkyl, benzyl or phenyl; and R 13 is phenyl or alkyl.