Diketene → HCID 21284013, compound

Temperature

-30 °C

0.76 ml Diketene is dissolved in 3.5 ml methylene chloride. The solution is cooled to -30° C. and a solution of 0.5 ml bromine in 3.5 ml methylene chloride is added slowly dropwise, after which stirring is continued at -30° C. for 10 mins. This solution is added quickly dropwise to a solution of glycine methyl ester prepared by suspending 1.25 g glycine methyl ester hydrochloride in 20 ml methylene chloride containing 2.8 ml triethylamine, stirring for 30 min and cooling to -30° C. The temperature is allowed to return to ambient with continued stirring. After filtering, and evaporating in vacuo at ambient temperature, the oil remaining is dissolved in 20 ml ethanol, cooled to 0° C. and treated with 100 mg NaBH4. After 5 min the excess hydride is destroyed with dilute acid, the ethanol is evaporated and the residue taken up with ethyl acetate; the solution is washed with brine, dried, evaporated, and purified by chromatography on silica, eluting with ethyl acetate. The title compound is obtained as a white powder, m.p. 60°-61° C.

1. customprepared
2. stirringstirring for 30 min
3. temperaturecooling to -30° C
4. filtrationAfter filtering
5. customevaporating in vacuo at ambient temperature
6. dissolutionthe oil remaining is dissolved in 20 ml ethanol
7. temperaturecooled to 0° C.
8. additiontreated with 100 mg NaBH4
9. customAfter 5 min the excess hydride is destroyed
10. additionwith dilute acid
11. customthe ethanol is evaporated
12. washthe solution is washed with brine
13. customdried
14. customevaporated
15. custompurified by chromatography on silica
16. washeluting with ethyl acetate

ORD record

ord-f5e2cc78fac241c892de1690888b6405

Source dataset

uspto-grants-1986_12

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04629797