N,N-DIMETHYLHYDROXYLAMINE HYDROCHLORIDE Property

Melting point:

107-109 °C (lit.)

BRN 

3905683

Safety

Hazard Codes 

Xi

Risk Statements 

36/38

Safety Statements 

26-36

WGK Germany 

3

F 

3

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

Precautionary statements

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P337+P313IF eye irritation persists: Get medical advice/attention.

N,N-DIMETHYLHYDROXYLAMINE HYDROCHLORIDE Chemical Properties,Usage,Production

Uses

N,N-Dimethylhydroxylamine hydrochloride was used in the synthesis of 4,4-dimethyl-2,5,5-triphenyl-l.3-dioxa-4-azonia-2-bora-5-boratacyclopentane. It was also used as a polymer-chain terminator.

Preparation

(a) Preparation of N,N-Dimethyl~(a-phenylethyl)amine Oxide. To a flask containing 11.0 g (0.074 mole) of N,N-dimethyl(a-phenylethyl)amine is added dropwise 18.3 g (0.19 mole) of 35% aqueous hydrogen peroxide, and the mixture is stirred for 11 hr at room temperature. The excess hydrogen peroxide is decomposed by stirring the mixture with 8 sqcm2 clean platinum foil until the evolution of oxygen ceases. Most of the water is removed by distillation at 35 mm Hg, at a bath temperature of 45-55°C. The material that condenses in the dry-ice trichloroethylene trap is saved for recovery in Procedure (b). The residual syrup is diluted with 25 ml of absolute ethanol, and the process is repeated twice while a capillary ni­trogen ebulliator is used. The resulting amine oxide is a viscous syrup and has a slight odor of styrene.
(b) Decomposition of N,N-Dimethyl-(a-phenylethyl)amine Oxide to Ν,Ν-Dimethylhydroxylamine. A 100 ml round bottom flask equipped with a capillary nitrogen inlet, and containing the preceding amine oxide is connected by a large-diameter tube to a condenser set for distillation with two receivers. Each receiver is cooled in a mixture of dry ice and trichlo­roethylene. The system is evacuated to 5 mm, and the flask is immersed in an oil bath at 85°C. The bath temperature is raised slowly to 115°C over a 35-min period, in which time most of the material distilled over. The bath temperature is finally raised to 150°C, in order to complete the (decom­position) distillation process. The residue remaining averages 0.35 g. The distillate in the dry-ice trap here and from Procedure (a) are combined, pentane is added as a solvent, and the mixture is washed with dilute hydrochloric acid. The acid solution is extracted with pentane, the latter washed with water until neutral.
The product is obtained from the combined aqueous layers containing hydrochloric acid by concentration under reduced pressure, to give a crys­talline residue. The latter, upon drying in a vacuum desiccator over P2O5 averages 6.73 g (94% yield), m.p. 101-101°C (sealed capillary). Recrys-tallization several times from a mixture of absolute ethanol and ether gives white, hygroscopic needles, m.p. 106.5-109°C (sealed capillary).