Patent ID: 8481751

Claim:
A method for production of a compound represented by formula (I) or a salt thereof, where X stands for a halogen radical, R 1 and R 2 are selected so that (1) R 1 is H and R 2 is CH 2 (CH 2 ) m COOR 3 , (2) R 1 is CH 2 (CH 2 ) m COOR 3 and R 2 is H, or (3) R 1 and R 2 together stand for a radical represented by formula (II) where each of R 3 , R 4 and R 5 stands independently for an alkyl radical, and where each of m and n represents independently a number in a range of 0-12, the method comprising reacting a compound represented by formula (III) with a mixture containing a compound (i) selected from the group consisting of a compound represented by formula (IV) where R 6 stands for H or an alkyl radical, and each of R 7 and R 8 stands independently for an alkyl radical, and of a compound represented by formula (V) where each of R 9 and R 10 stands independently for an alkyl radical, and this mixture also contains a compound (ii) represented by formula (VI)