N,N-Dimethylglycine → 2-(Dimethylamino)-N-hydroxy-N-methylacetamide

To the solution of 131 g of sodium hydroxide dissolved in 400 ml of water, 400 ml of an aqueous solution containing 273 g of N-methylhydroxylamine hydrochloride was added, with ice-cooling. Subsequently, 384 g of N,N-dimethylglycine methyl ester was added thereto. The resultant reaction mixture was stirred at room temperature for 3 days. The results of gas chromatography demonstrated a rate of residual raw materials: 2.3%, a rate of formation of N-methyl-α-dimethylaminoacetohydroxamic acid: 51.5%, and a rate of secondary production of N,N-dimethylglycine: 45.1%. After a large portion of the solvent was distilled off under a reduced pressure, chloroform and then anhydrous magnesium sulfate were added to the residue; thereafter, they were fully shaked, followed by filtration, to remove insoluble substances. After the resultant filtrate was concentrated, the residue was recrystallized from aceton/methanol (50/1), to give 186 g of crystals. As a result of analysis of the crystals using gas chromatography and 1H-NMR, it was found that each several percents of each of N,N-dimethylglycine and N-methylhydroxylamine were mixed therein, and therefore the crystals were dissolved again in 3 liters of chloroform, to remove insoluble substances by filtration. After the filtrate was concentrated, the residue was recrystallized from aceton/methanol (12/1), to give 111 g (yield 25.6%) of pure N-methyl-α-dimethylaminoacetohydroxamic acid.

1. customAs a result of analysis of the crystals
2. additionwere mixed
3. customto remove insoluble substances
4. filtrationby filtration
5. concentrationAfter the filtrate was concentrated
6. customthe residue was recrystallized from aceton/methanol (12/1)

ORD-Eintrag

ord-5a69892ec8204ed1ad5021b701e4c0c9

Quelldatensatz

uspto-grants-2000_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06153793