GB808294A - Improved process for the preparation of alkyl and cycloalkyl nitrates - Google Patents

Abstract

Alkyl or cycloalkyl nitrates are prepared by introducing at least one primary or secondary monohydric aliphatic alcohol, or secondary monohydric cycloaliphatic alcohol, wherein said alcohol contains less than nine carbon atoms, into a reaction medium comprising from 15 to 50 per cent by weight sulphuric acid, 10 to 30 per cent by weight nitric acid, 30 to 50 per cent by weight water and at least 1 per cent, preferably 1 to 10 per cent, by weight urea, said medium being maintained at a temperature between 65 DEG and 110 DEG C. The alkyl or cycloalkyl nitrate may be separated from the reaction mixture by distillation, by settling and withdrawal of the alkyl nitrate layer, by centrifuging or by solvent extraction. The process may be operated batchwise or continuously and in the latter case nitric acid and water are introduced concurrently with the alcohol at such a rate as to maintain the nitric acid-water ratio of the reaction medium substantially constant. The process is most effective with alcohols having no more than 8 carbon atoms, suitable alcohols being ethanol, n-propanol, iso-propanol, mixed pentanols, cyclohexanol and 2-octanol. Detailed examples illustrate the nitration of the above-mentioned alcohols with varying temperatures and concentrations of nitration mixture.