Chemical Identity:

• Chemical Name: N-O Dimethylhydroxylamine Hydrochloride

• Common Abbreviation: DMHA·HCl or N-O DMHA HCl

• Molecular Formula: C2H7ClNO

• Molecular Weight: ~97.54 g/mol

• Appearance: Usually a white to off-white crystalline solid

• Solubility: Highly soluble in water, soluble in alcohols

Structure and Functional Groups:

• The molecule contains a hydroxylamine group (–NHOH), but in this compound, the nitrogen is dimethylated, meaning two methyl groups (-CH3) are attached to the nitrogen atom.

• The hydrochloride (HCl) part indicates it is a salt formed by protonation of the basic nitrogen and association with chloride anion (Cl⁻).

Simplified structure:
(CH3)2N–OH · HCl

Synthesis and Preparation:

• Typically synthesized by methylation of hydroxylamine derivatives or by direct reaction of hydroxylamine hydrochloride with dimethylating agents (e.g., dimethyl sulfate, methyl iodide) under controlled conditions.

• Care is needed to avoid over-methylation or decomposition.

• Purified by recrystallization or extraction methods.

Chemical Properties:

• Acts as a nucleophilic reagent due to the lone pair on nitrogen and oxygen atoms.

• The N–O bond is reactive in some synthesis pathways.

• The hydrochloride salt form stabilizes the compound for handling and storage.

Applications in Synthesis:

• Commonly used as an intermediate or reagent in organic synthesis, especially for introducing the N–O functional group or for oximation reactions.

• Can be used to prepare oximes or as a precursor to other nitrogen-oxygen containing compounds.

• Its reactivity is exploited in synthesizing pharmaceuticals, agrochemicals, and fine chemicals.

Handling and Safety:

• Should be handled with care in a well-ventilated area.

• Can be irritant to skin and mucous membranes.

• The hydrochloride salt is generally more stable and less volatile than the free base form.

• Store in a cool, dry place, away from strong oxidizers and acids.