Water → 89364-92-1

Water (500 ml) is added dropwise over a period of 2 hours to a vigorously stirred, room temperature mixture of ethyl cyanoacetate (100 g, 0.884 mol), hydroxylamine hydrochloride (3 g, 1.328 mol) and sodium carbonate (70 g, 0.66 mol ) in ethanol (1 L.) After stirring for an additional 12 hours at room temperature, the reaction mixture is heated to 50° C. for 1 hour. The resulting light red colored solution is allowed to cool to room temperature and then stirred for an additional 2 hours. The solids formed are removed via filtration and the filtrate is concentrated in vacuo. The resulting residue is extracted with methylene chloride (3×200 ml). The combined organic extracts are washed with brine (300 ml), dried (Na2SO4), filtered and concentrated to afford 85.2 g (66%) of compound 2b as a slightly colored solid. Compound 2b can be further purified by crystallization from chloroform and hexanes. 1H NMR (CDCl3): δ8.45 (br s, 1H), 5.25 (br s, 2H) 4.25(q, 2H), 3.15 (s, 2H), 1.35 (t, J=7 Hz, 3H).

1. stirringAfter stirring for an additional 12 hours at room temperature
2. temperaturethe reaction mixture is heated to 50° C. for 1 hour
3. temperatureto cool to room temperature
4. stirringstirred for an additional 2 hours
5. customThe solids formed
6. customare removed via filtration
7. concentrationthe filtrate is concentrated in vacuo
8. extractionThe resulting residue is extracted with methylene chloride (3×200 ml)
9. washThe combined organic extracts are washed with brine (300 ml)
10. dry with materialdried (Na2SO4)
11. filtrationfiltered
12. concentrationconcentrated

ORD record

ord-014132e706604526a6c41d028a4350cf

Source dataset

uspto-grants-2005_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06951946B2