| 摘要 |
<p>Dienes and/or aromatics and/or naphthenes are sepd. from hydrocarbon fractions by liq./liq. extn. and/or extractive distn., using a cyanamide solvent, opt. mixed with water or a third solvent. The solvents are N-cyanodialk(en)ylamines or heterocyclic N-cyanides. They are most economically prepd. by reacting Br2 with a cyanide, e.g. NaCN, in an aq. medium, followed by reaction with sec. or cyclic amine, giving about 80% yields. The N-cyanodialk(en)ylamines are of formula R1R2N-CN (where R1 and R2 are not >4C (un)branched alkyl gps. or R1 is a not >4C alkenyl gp. opt. carrying alkyl substits. and R2 is the same as R1 or is a not >4C (un)branched alkyl. The heterocyclic cyanides are of formula N-CN, where N forms part of a 3-6 member chain. and the ring may contain other hetero atoms, e.g. O.</p> |
