Patent ID: 8664428

Claim:
A process for preparing a compound of formula (I), characterized in that 1-tert-butyl-3,5-dimethylbenzene is reacted with a compound of formula (VI) to give a compound of the formula (V) which is subsequently reduced to a compound of formula (IV); the compound of formula (IV) is converted by removal of the tert-butyl radical into a compound of formula (III), and bromination of the compound of formula (III) gives a compound of formula (II) which, using a compound of formula (A) in the presence of a base and a palladium catalyst, optionally in a solvent, is converted into a biphenyl compound of formula (I): in which R represents hydrogen, C 1 -C 6 -alkyl or phenyl, R′ represents hydrogen or C 1 -C 6 -alkyl, R″ represents hydrogen or a radical R′CO, R 2 represents hydrogen, halogen, C 1 -C 6 -alkyl, C 2 -C 6 -alkenyl, C 2 -C 6 -alkynyl, C 1 -C 6 -alkoxy, C 1 -C 6 -haloalkyl, C 1 -C 6 -haloalkoxy, cyano, or nitro, n represents 0, 1, 2 or 3, and A is selected from the groups below: (a) boronic acid of the formula (A-a), in which m represents 2, p represents 1, Q represents a hydroxyl group, or the anhydrides, dimers and trimers formed therefrom, and R 2 and n are as defined above, (b) cyclic boronic esters of the formula (A-b), in which m represents 2, represents 1, Q represents a C 1 -C 4 -alkoxy group, where the two Q substituents together with the boron atom to which they are attached via the oxygen atom form a 5- or 6-membered ring which is optionally substituted by C 1 -C 4 -alkyl, and R 2 and n are as defined above, (c) boronates of the formula (A-c), in which m represents 3, p represents 1, Q represents hydroxy, fluorine, C 1 -C 4 -alkoxy or C 6 -C 10 -aryloxy and where the negative charge of the boron ion is compensated by a cation, and R 2 and n are as defined above, (d) a diphenylboric acid of the formula (A-d), in which m represents 1, p represents 2, Q represents hydroxy, C 1 -C 4 -alkoxy or C 6 -C 10 -aryloxy, and R 2 and n are as defined above, (e) a triarylborate salt of the formula (A-e), in which m represents 0, p represents 3, and R 2 and n are as defined above, (f) a difluoroborate salt of the borinic acid of the formula (A-f), in which m represents 2, p represents 2, Q represents fluorine, where the negative charge of the boron ion is compensated by a cation, and R 2 and n are as defined above, (g) a tetraarylborate salt of the formula (A-g), in which m represents 0, p represents 4, where the negative charge of the boron anion is compensated by a cation, and R 2 and n are as defined above.