Patent ID: 7902175

Claim:
A process for producing a compound of the formula II wherein each of m and n, independently, is 1, 2 or 3 X is O or a direct bond; R 1 is a phenylalkyl wherein alkyl is a straight- or branched (C 6-20 )carbon chain; or a phenylalkyl wherein alkyl is a straight- or branched (C 1-30 )carbon chain wherein said phenylalkyl is substituted at the phenyl residue by a straight- or branched (C 6-20 )carbon chain optionally substituted by halogen, a straight- or branched (C 6-20 )alkoxy chain optionally substituted by halogen, a straight- or branched (C 6-20 )alkenyloxy, phenylalkoxy, halophenylalkoxy, phenylalkoxyalkyl, phenoxyalkoxy or phenoxyalkyl, cycloalkylalkyl substituted by C 6-20 alkyl, heteroarylalkyl substituted by C 6-20 alkyl, heterocyclic C 6-20 alkyl or heterocyclic alkyl substituted by C 2-20 alkyl, and wherein the alkyl moiety may have in the carbon chain, a bond or a heteroatom selected from a double bond, a triple bond, O, S, sulfinyl, sulfonyl, or NR 5 , wherein R 5 is H, alkyl, aralkyl, acyl or alkoxycarbonyl, and as a substituent alkoxy, alkenyloxy, alkynyloxy, aralkyloxy, acyl, alkylamino, alkylthio, acylamino, alkoxycarbonyl, alkoxycarbonylamino, acyloxy, alkylcarbamoyl, nitro, halogen, amino, hydroxy or carboxy, and R 2 is wherein each of R 3 and R 4 , independently, is H or C 1-4 alkyl, wherein alkyl optionally substituted by 1, 2 or 3 halogen atoms; or a pharmaceutically acceptable salt thereof; and wherein greater than 70% of the compound by weight is in the form of the R or S enantiomer; comprising deprotecting a compound of formula III, IIIa or IIIb wherein greater than 70% by weight of the compound of formula III, IIIa or IIIb is in the form of the R or S enantiomer wherein n, m, X, R 1 and R 2 are as defined above, R 6 is an amino protecting group, and R 6 ′, is an amino protecting group such that R 6 ′, together with the oxygen and nitrogen atoms to which it is attached, the asymmetric carbon atom and 1 to 3 additional carbon atoms forms a 5 to 7 membered heterocyclic ring; and, where required, converting the compounds of formula II obtained in free form into the salt form, or vice versa.