Hydrochloric Acid → HCID 54128125, compound

18.04 g (0.2 mol) of a 50% aqueous solution of dimethylamine in 10 ml toluene was cooled in an ice bath and combined with 8.41 g (0.1 mol) of a diketene in 20 ml of toluene and stirred for 1 hour at room temperature. After distilling water off azeotropically, 200 ml of ethyl acetate was added and the mixture was dried over with anhydrous sodium sulfate to distill the solvent off. To the residue thus obtained, 7.63 g (0.105 mol) of sodium nitrite was added and the mixture was cooled in an ice bath and then 10 ml (0.12 mol) of a concentrated hydrochloric acid was added dropwise. After stirring for 0.5 hour at room temperature, the reaction mixture was cooled again in an ice bath, and 5.42 g (0.13 mol) of sodium hydroxide was added. The solution thus obtained was added to a solution of 18.92 g (0.15 mol) of dimethyl sulfate and 1.61 g (0.05 mol) of tetrabutylammonium bromide in 50 ml of toluene dropwise while cooling with an ice, and the mixture was stirred for 4 hours at room temperature. The reaction mixture was extracted four times with 150 ml of ethyl acetate and dried over with anhydrous magnesium sulfate, and then the solvent was distilled off, and finally the residue thus obtained was purified by a column chromatography on a silica gel (n-hexane/ethyl acetate) to obtain 13.46 g (yield: 78%) of 2-methoxyimino-N,N-dimethylacetoacetamide as a colorless crystal.

1. distillationAfter distilling water off azeotropically, 200 ml of ethyl acetate
2. additionwas added
3. dry with materialthe mixture was dried over with anhydrous sodium sulfate
4. distillationto distill the solvent off
5. customTo the residue thus obtained
6. temperaturethe mixture was cooled in an ice bath
7. stirringAfter stirring for 0.5 hour at room temperature
8. temperaturethe reaction mixture was cooled again in an ice bath
9. customThe solution thus obtained
10. stirringthe mixture was stirred for 4 hours at room temperature
11. extractionThe reaction mixture was extracted four times with 150 ml of ethyl acetate
12. dry with materialdried over with anhydrous magnesium sulfate
13. distillationthe solvent was distilled off
14. customfinally the residue thus obtained
15. customwas purified by a column chromatography on a silica gel (n-hexane/ethyl acetate)

ORD record

ord-c2531af0210149d198be39f8f8c2dc42

Source dataset

uspto-grants-2001_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06251949B1