Thermolysis of tris (isopropylamino) borane (1) and its reaction with ammonia were investigated. Compound 1 exhibited good thermal stability resulting in almost complete evaporation during its thermogravimetric analysis under Ar up to 1000° C. Refluxing of 1 for 42 h at 250° C produced its conversion into the expected B, B′, B′-tris (isopropylamino)- N, N′, N ″-triisopropylborazine (2), and into the new intermediate [(NHPri) 2B] 2NPri (3), ...