Nitrogen nucleophiles include ammonia, azide, amines, nitrites, hydroxylamine, hydrazine, carbazide, phenylhydrazine, semicarbazide, and amide. These include hydrazine, hydroxylamine, the hypochlorite ion and the hydroperoxide anion. Microwave irradiation of phthalic anhydride and hydroxylamine hydrochloride in pyridine produces "N"-hydroxyphthalimide in 81% yield. Intermediates in this process are two highly toxic compounds, hydrazine (NH) and hydroxylamine (NHOH). Oximes can be synthesized by condensation of an aldehyde or a ketone with hydroxylamine. Hydroxylammonium chloride is the hydrochloric acid salt of hydroxylamine. The product is then treated with hydroxylamine hydrochloride, to yield an oxime. Hydroxylammonium sulfate (NHOH)SO, is the sulfuric acid salt of hydroxylamine. In place of the amine, hydroxylamine esters and nitroarenes have been reported as nitrogen sources. Further reduction of the hydroxylamine leads to the amine. Oximes are usually generated by the reaction of hydroxylamine with aldehydes or ketones. The chloride sites on "p"-DCB can be substituted with hydroxylamine and sulfide groups. Hydrazines and hydroxylamine can be used in place of amines. Aliphatic nitro compounds are however more difficult to reduce, often remaining as the hydroxylamine. It was shown to hydrolyze to serine and hydroxylamine.