The Synthesis Of O-Substituted Hydroxylamines And Their Derivatives

O-substituted alkyl hydroxylamines are a kind of expensive intermediates, which are widely used in organic synthesis and can be used as alkoxyl amination reagents. They have a wide range of application in medicine and pesticide fields, especially in the synthesis of some oxime ethers compounds, such as herbicides, fungicides and so on.In this paper, an efficient route to prepare O-substituted alkyl hydroxylamines was chosen according to the old methods. They were synthesized using hydroxylamine hydrochloride and ethyl acetate as raw materials via acetylamination, O-alkylation and hydrolysis. Four representative alkylating reagents were selected, containing1,3-dichloropropene, n-butyl bromide, cyclohexylmethyl bromide, benzyl chloride.And corresponding O-(3-chloro-2-propenyl) hydroxylamine, O-(n-butyl) hydroxylamine, O-methyl cyclohexyl hydroxylamine and O-benzyl hydroxylamine. The products and intermediates were characterized by H-NMR.Meanwhile, the influence of reaction conditions was studied through a series of parallel experiment. With optimization of the parameters, such as the feeding ratio, the type and the dosage of alkali catalysts, reaction temperature, reaction time, the yield of production has been remarkably improved.In addition, O-phenyl hydroxylamine can not be synthesized using the above route. Meanwhile, it was synthesized from N-hydroxyphthalimide and phenylboronic acid through two steps, including arylation, hydrolysis. With further optimization of the synthetic conditions, such as the feeding ratio, solvent, the type and the dosage of alkali catalysts, the optimized parameters were achieved.