Abstract: A process for the production of tetra- and trialkylsilanes which comprises reacting(A) an alkylchlorosilane having the formulaR.sub.x SiCl.sub.(4-x)wherein R is an alkyl radical containing from one to three carbon atoms per molecule and x is an integer from 0 to 3, with(B) a trialkylaluminum compound having the formula ##STR1## wherein R.sub.1, R.sub.2 and R.sub.3 are the same or different and represent alkyl radicals containing from 6 to 20 carbon atoms per molecule, in a reaction zone, said reaction being conducted under hydrosilylation conditions. Selectivity to tetra- or trialkylsilanes, respectively, is controlled by the addition of particular alkaline metal salts to the reaction zone.

Abstract: A process for the preparation and recovery of m,m'-dinitrobenzophenone and which comprises reacting benzophenone with nitric acid in oleum; adjusting the reaction product to a water content from 12 to 30 weight percent; and extracting the m,m'-dinitrobenzophenone with a chlorinated hydrocarbon solvent.

Abstract: A one-step solution technique for preparing an aromatic polyimide acid which comprises reacting an aromatic dianhydride with an aromatic diamine in the presence of diglyme and a sufficient amount of a co-solvent to maintain the polyimide acid in solution, said co-solvent having the formula:ROHwhere R is H, an aliphatic branched or straight-chain hydrocarbon having from 1 to 5 carbon atoms or a methoxy substituted aliphatic branched or straight-chain hydrocarbon having from 1 to 5 carbon atoms.

Abstract: A one-step solution technique for preparing an aromatic polyimide acid which comprises reacting an aromatic dianhydride with an aromatic diamine in the presence of propylene glycol methyl ether.

Abstract: A process for recovering maleic anhydride from gaseous compositions comprising maleic anhydride and water by condensing the composition at a temperature in the range of from about 20.degree. C. to about 50.degree. C. and a pressure of less than about 200 millimeters of mercury.

Abstract: A process for producing maleic anhydride from a C.sub.4 hydrocarbon selected from n-butane and n-butene feed which comprises: (a) feeding the C.sub.4 hydrocarbon and air to a reactor; (b) contacting the C.sub.4 hydrocarbon and air in the reactor with a catalyst comprising vanadium and phosphorus oxides at reaction conditions including a temperature between 550.degree. and 1000.degree. F. so as to obtain a reactor effluent containing maleic anhydride, unreacted butane, nitrogen, oxygen, and acrylic, acetic or maleic acid or mixtures of the foregoing acids; (c) removing maleic anhydride from the reactor effluent to obtain maleic anhydride-lean effluent; (d) removing said acids from at least a portion of the maleic anhydride-lean effluent to obtain a purified recycle stream containing less than 100 ppm of the acids; and (e) recycling the purified stream to the reactor. Preferably the acids are removed in step (d) by water and/or caustic scrubbing the maleic anhydride-lean effluent.

Abstract: A process for producing maleic anhydride from n-butane which comprises:(a) feeding n-butane and air to a reactor;(b) contacting the butane and air with a catalyst comprising vanadium and phosphorus oxides at reaction conditions including a temperature between 550.degree. F. and 1000.degree. F. so as to convert 15 to 28% of the butane per pass and obtain a reactor effluent containing maleic anhydride, unreacted butane, nitrogen, and oxygen;(c) removing maleic anhydride from the reactor effluent to obtain maleic anhydride-lean effluent;(d) recycling a portion of the maleic anhydride-lean effluent to the reactor;(e) removing butane from the other portion of the maleic anhydride-lean effluent; and(f) recycling the removed butane to the reactor.Preferably the temperature in, and/or space velocity through, the reactor is adjusted to obtain a weight percent selectivity to maleic anhydride of at least 90% of the butane converted.

Abstract: The hydrogen fluoride-catalyzed carbonylation of formaldehyde to prepare glycolic acid can be carried out with a significant reduction in by-product formation and at a significantly improved rate by incorporating minor amounts of acetic acid in the reaction medium.

Abstract: The catalytic properties of a complex catalyst comprising vanadium, phosphorus and oxygen which is used for the oxidation of hydrocarbons to maleic anhydride can be partially regenerated by contacting the catalyst with sulfur trioxide.