Carbon Dioxide → HCID 73447335, compound

Temperature

23 °C

At 10° C., 200 g of methyl 2-acetyl-4-methylpent-4-enoate (preparation: cf. Tetrahedron (1985) 4633) in 2000 ml of aqueous 10% strength potassium hydroxide solution were admixed with 85 g of sodium nitrite, and the mixture was stirred at 23° C. for 18 hours. With ice-cooling, 1000 ml of 10% strength sulfuric acid were subsequently added dropwise such that the internal temperature remained below 10° C. The mixture was then stirred at 10° C. until evolution of CO2 had ceased. For work-up, the mixture was extracted with methyl tert-butyl ether, the combined organic phases were extracted with 3 N aqueous sodium hydroxide solution and the alkaline phases were adjusted to pH 1 using 20% strength sulfuric acid. They were then extracted with methylene chloride, the extract was dried over sodium sulfate and the solvent was removed under reduced pressure. This gave 142 g of the title compound as a yellow oil which crystallized on standing.

1. customAt 10° C.
2. temperatureWith ice-cooling
3. customremained below 10° C
4. extractionFor work-up, the mixture was extracted with methyl tert-butyl ether
5. extractionthe combined organic phases were extracted with 3 N aqueous sodium hydroxide solution
6. extractionThey were then extracted with methylene chloride
7. dry with materialthe extract was dried over sodium sulfate
8. customthe solvent was removed under reduced pressure
9. customThis gave 142 g of the title compound as a yellow oil which crystallized

ORD record

ord-7b550e9296ce40d881e5912f97a8bdc6

Source dataset

uspto-grants-2002_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06344589B1