GB609022A - Improvements in and relating to the production of organic nitrogen compounds - Google Patents

Abstract

Nitro - compounds of saturated aliphatic hydrocarbons are prepared by reacting aliphatic mono-olefines containing from 3 to 6 carbon atoms with nitrogen trioxide, or nitric oxide, and oxygen or an oxygen-containing gas such as air in the presence of a solvent as hereinafter defined, but excluding the process in which prior to contact with the olefine, the nitrogen oxide and oxygen or oxygen-containing gas are reacted together and in which the nitrogen oxide content of the reacted mixture is present as nitrogen tetroxide. The solvents comprise those defined in Specification 580,260, namely, saturated aliphatic, alicyclic-aliphatic or alicyclic compounds containing carbon, hydrogen and oxygen only and having no oxygen-containing groups except ether or ester groups and no 3-or 4-membered rings, but excluding formic acid esters; saturated heterocyclic or aliphatic-heterocyclic compounds containing carbon, hydrogen and oxygen only and having only carbon and oxygen in the ring and no other groups except hydrogen, hydrocarbon, ether or ester groups, but excluding such compounds containing 3- or 4-membered rings. Nitration may be effected preferably at atmospheric temperature and pressure using solutions of the reactants in the specified solvents or the nitrogen oxide and oxygen may be passed continuously through a solution of the olefine. With gaseous olefines, the olefines and oxygen are preferably passed through a solution of the nitrogen oxide. Normally, anhydrous conditions are employed. The oxygen may be introduced at any stage in the process. The olefines may be used pure, as mixtures or with diluents. The products comprise dinitro compounds, nitro/nitrates and nitrites. To facilitate working up, the crude mixture is treated with water or an aliphatic alcohol having less than 6 carbon atoms whereby nitrites present are decomposed to nitro-alcohols. A number of methods of separating the various products are described. Compounds which may be prepared are 1 : 2-dinitropropane, 1-nitropropanol-2 and its nitrate from propylene and 1 : 2-dinitroisobutane, nitro-t-butanol and its nitrate from isobutene. Specification 583,468 also is referred to. According to the Provisional Specification the mono-olefines may contain substituent groups which may be aromatic.