Prepn. of derivs. of phenyl-tetrazole - by reacting benzeneboronic acid deriv. with aryl halide in presence of a palladium catalyst

摘要

Prodn. of phenyul-tetrazole derivs. of formula (I) is claimed. In (I), R1,R2,R3 = 1-2C alkyl or aryl; Ar = aryl-naphthyl, pyridinyl-pyrimidyl, quinolinyl or imidazo-pyridinyl (all opt. substd.). A benzo-boronic acid is reacted with a deriv. of formula ArZ (III), where Z = Cl, I or Br in a solvent and in the presence of a base and catalyst. The pref. benzene-boronic deriv. is (2-(2-(1,1-dimethylethyl) -2H-tetrazole-5-yl)-phenyl) boronic acid (IIa). Solvent is e.g. benzene-toluene, dimethyl-formamide or 1,2-dimethoxy-ethane, esp. toluene. Pref. bases are Na2CO3, K2CO3, KH2PO4 or a tert. amine, esp. NaCO3. The catalyst is palladium tetrakis (triphenylphosphine). USE - The reaction provides a method for obtaining direct aryl-aryl, aryl-naphthyl and aryl-heterocyclic couplings, in the presence of a Pd catalyst.