Reaktion #629322

Reaktionsgleichung

product

Ethyl 3-amino-2-propionyl-4,4,4-trifluorocrotonate

LDA

n-BuLi

diisopropylamine

ethyl pentafluoropropionate

→

beige solid

Ausbeute 30.7%

Ethyl 4-hydroxy-5-methyl-6-(pentafluoroethyl)-2-(trifluoromethyl)-3-pyridinecarboxylate

Ausbeute 30.7%

Lösungsmittel

water

ether

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto maintain a temperature below -60° C
2. 2
   workup.STIRRINGAfter stirring at -78° C. for 15 minutes
3. 3
   Extraktionextracted with ether
4. 4
   ExtraktionThe ether extract
5. 5
   Extraktionwas extracted with 10% K2CO3
6. 6
   ExtraktionThe combined aqueous layer and K2CO3 extract

Vorschrift

To a -78° C. solution of LDA (0.10 mol), prepared from 0.10 mol of n-BuLi and 14 ml (0.10 mol) of diisopropylamine in 70 ml ether was added a solution of 10.0 g (0.042 mol) of product of Example 34 in 20 ml of ether slowly to maintain a temperature below -60° C. After stirring for 30 minutes, the reaction mixture was treated with 21 ml (0.042 mol) of ethyl pentafluoropropionate. After stirring at -78° C. for 15 minutes, the reaction mixture was warmed to 10° C. in 0.5 hour and poured into 100 ml of water, and extracted with ether. The ether extract was extracted with 10% K2CO3. The combined aqueous layer and K2CO3 extract was acidified with concentrated HCl to give 4.73 g (29.5%) of beige solid; mp 115°-117° C. (dec). A 2.73 g (0.00709 mol) of the solid was heated in a kugelrohr pot at 130° C. for 0.5 hour. The distillate and residue were combined and dissolved in ether. The ether solution was dried (CaSO4) and concentrated to give 2.0 g (76.9%) of product as a solid; mp 36°-38° C.

Quelle