Patent ID: 8304548

Claim:
A method for producing a compound represented by formula (III): wherein A 1 , A 2 , A 3 , A 4 and A 5 are as defined below, or a salt thereof, which comprises reacting a compound represented by formula (1): wherein each of A 1 , A 2 , A 3 and A 4 , which may be the same or different, is a hydrogen atom, an optionally substituted 6- to 14-membered aromatic hydrocarbon ring group or an optionally substituted 5- to 14-membered heteroaromatic ring group, and X is a leaving group, or a salt thereof with a compound represented by formula (II): wherein A 5 is an optionally substituted 6- to 14-membered aromatic hydrocarbon ring group or an optionally substituted 5- to 14-membered heteroaromatic ring group; and R1 and R2 are as follows: 1) each of R1 and R2, which may be the same or different, is a hydrogen atom or a C1-6 alkyl group, and 2) the compound of formula (II) may form boroxine (a trimer) when both R1 and R2 are hydrogen atoms, or 3) R1, R2, the oxygen atoms and the boron atom, when taken together, form a 5- or 6-membered ring group optionally substituted by one to four C1-6 alkyl groups, in the presence of a palladium compound, a copper compound, a phosphorus compound and a base.