Triarylborane derivative, preparation thereof and use thereof as synthesis intermediate

PURPOSE: To provide novel compounds useful as synthesis intermediates which give intermediates of angiotensin II antagonist in high purity and high yield. CONSTITUTION: The objective compounds are represented by formula I [wherein R is -CR 1 R 2 R 3 or -Si(R 5 ) 3 (wherein R 1 -R 3 are each 1-2C alkyl or benzyl; and R 5 is 1-2C alkyl or aryl), provided that R is in the 1- or 2-position of a tetrazole ring], e.g. 5,5',5"-[borylidynetris(1,2-phenylene)]tris[2-(1,1-dimethylethyl)-2H- tetrazole]. The compounds can be obtained by reacting a derivative of formula II (wherein Z is H or a halogen) with an alkyllithium such as n-butyllithium in an aprotic solvent such as THF at a temperature of 20°C to a refluxing temperature to obtain an organolithium reagent and then, reacting the reagent with a 1-4C trialkyl borate such as trimethyl borate or a trihaloborane in an aprotic solvent. COPYRIGHT: (C)1995,JPO