Reactive Group Datasheet


Not highly flammable, but may be combustible.
Oximes behave as weak acids and bases. Aldoximes can peroxidize and explode during distillation. In the presence of even trace amounts of acid, ketoximes can undergo an exothermic acid-catalyzed rearrangement called the Beckmann rearrangement. The product of the rearrangement is a stable amide; however, the reaction can be exothermic enough to cause the explosion of unreacted starting material. The presence of acidic salts significantly lowers the temperature required for this explosion. The hydrolysis of oximes proceeds easily by heating in the presence of various inorganic acids, and the oximes decompose into the corresponding ketones or aldehydes, and hydroxylamines. Oximes may decompose upon heating, resulting in an explosive event.
Some may be very toxic. For example, aldicarb oxime, the hydrolysis product of the carbamate ester pesticide aldidarb, can have nervous system effects.
Other Characteristics
Compounds containing a C=N-O-R structure. They can be produced by the condensation of aldehydes or ketones with hydroxylamines. Oximes derived from aldehydes have at least one hydrogen atom on the C=N carbon atom, and are called aldoximes. Oximes derived from ketones do not have any hydrogen atoms on the C=N carbon, and they are called ketoximes. Aldoximes tend to be more reactive than ketoximes. Oximes are found in some pesticides (as oxime carbamates) and in some pharmaceutical compounds. The largest industrial use for oximes is as an intermediate in the industrial production of caprolactam, a precursor to Nylon 6.
Aldicarb oxime, dimethyl glyoxime, methoxime.