Tree method of producing the cyclic ether

摘要

Benzimidazole derivs. of formula (I) and their salts are new. R is a bond and R1 is a totally or partially fluorinated 1-2C alkylene gp. or a chlorotrifluoroethylene gp., or R = R1 = CF2; R2 = H or 1-3C alkyl; R3 = H, 1-3C alkyl or 1-3C alkoxy; R4 = H or 1-3C alkyl; n = 0 or 1.