Reaktion #157116

Reaktionsgleichung

mucobromic acid

NaOEt

2,6-difluorobenzimidamide hydrochloride

→

5-bromo-2-(2,6-difluorophenyl)pyrimidine-4-carboxylic acid

Lösungsmittel

EtOH

EtOH

EtOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturcooled
2. 2
   Temperaturthe reaction was heated in a 50° C. oil bath for 2.5 hr
3. 3
   TemperaturAfter cooling to rt the reaction mixture
4. 4
   Einengenwas concentrated in vacuo
5. 5
   workup.ADDITIONH2O and 1.0 N NaOH were added
6. 6
   Waschenthe aqueous mixture was washed with EtOAc
7. 7
   Extraktionthen extracted with EtOAc
8. 8
   WaschenCombined organic extracts were washed once with brine
9. 9
   Trocknendried over anhydrous Na2SO4
10. 10
    Filtrationfiltered
11. 11
    Einengenconcentrated in vacuo

Vorschrift

A 2.68 M NaOEt in EtOH solution (3 eq) was added to an ice-bath cooled mixture of 2,6-difluorobenzimidamide hydrochloride (2 eq) in EtOH (0.1 M). The resulting mixture was allowed to warm to rt and stirred under N2 for 30 min. To the reaction mixture was added drop wise a solution of mucobromic acid (1 eq) in EtOH and the reaction was heated in a 50° C. oil bath for 2.5 hr. After cooling to rt the reaction mixture was concentrated in vacuo. H2O and 1.0 N NaOH were added and the aqueous mixture was washed with EtOAc. The aqueous phase was acidified to pH=4 with 1.0 N HCl then extracted with EtOAc. Combined organic extracts were washed once with brine, then dried over anhydrous Na2SO4, filtered, and concentrated in vacuo to give 5-bromo-2-(2,6-difluorophenyl)pyrimidine-4-carboxylic acid. The crude product was used for the next step without further purification. LC/MS (m/z): 316.9 (MH+). LC: Rt: 2.426 min.

Quelle