Synthesis of Isopropyldichlorosilane by Direct Process

摘要

Direct reaction of elemental silicon with a gaseous mixture of isopropyl chloride (1) and hydrogen chloride in the presence of copper catalyst using a stirred bed reactor equipped with a spiral band agitator gave isopropyldichlorosilane having a Si-H bond (2a) as a major product and isopropyltrichlorosilane (2b) along with chlorosilanes,trichlorosilane and tetrachlorosilane.A process for production of 2a was maximized using the 1:0.5 mole ratio of 1 to HC1 and smaller size of elemental silicon at a reaction temperature of 220 °C.When a reaction was carried out by feeding a gaseous mixture of 1 [12.9 g/h (0.164 mol/h)] and HC1 [2.98 g/h (0.082 mol/h)] to a contact mixture of elemental silicon (360 g) and copper (40 g) under the optimum condition for 45 h,2a among volatile products kept up about 82 mol % until 35 h and then slowly decreased down 68 mol % in 45 h reaction.Finally 2a was obtained in 38% isolated yield (based on 1 used) with an 85% consumption of elemental silicon in a 45 h reaction.In addition to 2a,2b was obtained as minor product along with chlorosilanes,trichlorosilane,and tetrachlorosilane.The decomposition of 1 was suppressed and the production of 2a improved by adding HC1 to 1.