N,O-Dimethylhydroxylamine is a methylated hydroxylamine used to form so called 'Weinreb amides' for use in the Weinreb ketone synthesis.[1] It is commercially available as its hydrochloride salt.
It may be prepared by reacting ethyl chloroformate (or similar) with hydroxylamine followed by treatment with a methylating agent such as dimethyl sulfate. The N,O-dimethylhydroxylamine is then liberated by acid hydrolysis followed by neutralization.