Synthesis of tetraalkylsilanes

An improvement in a process for preparing a tetrahydrocarbylsilane of the formula ##STR3## wherein each of R and R.sup.1 is a hydrocarbyl group having less than 8 carbon atoms, the process comprising:

• a) forming a reaction mass of molten alkali metal and a hydrocarbon solvent at a temperature of from about 100.degree. to about 130.degree. C.;
• b) charging R.sub.3 Al to the reaction mass while maintaining the reaction mass under an inert gas atmosphere;
• c) cooling the reaction mass to a temperature within the range of 20.degree. to 100.degree. C;
• d) feeding R.sup.1 SiCl.sub.3 to the cooled reaction mass;
• and
• e) subsequently, heating the reaction mass to a temperature above about 100.degree. C. for a period of time sufficient to form the tetrahydrocarbylsilane
• wherein the pressure during the reaction is less than about 3000 kPa.

A process for preparing organotri-n-butylsilane in high yield, comprising:

• a) forming a reaction mass from molten sodium and tri-n-butyl aluminum, in an hydrocarbon solvent under an nitrogen atmosphere;
• b) maintaining the reaction mass at a temperature in the range of from about 100.degree. to about 130.degree. C. for a period of time sufficient to form sodium tetra-n-butylaluminate;
• c) contacting the sodium tetra-n-butylaluminate with R.sup.1 SiCl.sub.3 ;
• and
• d) heating the contacted tetra-n-butylaluminate and R.sup.1 SiCl.sub.3 to a temperature and for a period of time sufficient to form the organotri-n-butylsilane
• wherein the tetra-n-butylaluminate and organotri-n-butylsilane are formed at a pressure of less than about 3000 KPa.