2,2,2-Trifluoroethanol → 5-Nitro-2-(2,2,2-trifluoroethoxy)pyridine

In a 250 mL four-necked flask, sodiumhydride (60% in mineral oil, 4.16 g) was combined with DMF (60 mL). The suspension was cooled to 0° C. and 2,2,2-trifluoroethanol (10.4 g, [CAS Reg. No. 75-89-8]) was added dropwise over a period of 20 minutes to the cold suspension. The mixture was stirred for 1 hour at 0° C. Then, a solution of 2-chloro-5-nitropyridine (15 g, [CAS Reg. No. 4548-45-2]) in DMF (70 mL) was added dropwise over a period of 20 minutes to the cold reaction mixture. Stirring was continued for 10 minutes at 0° C. and for 2 hours at r.t. The reaction mixture was poured into ice/water and was then extracted two times with ethyl acetate. The combined organic layers were washed with brine, dried over Na2SO4, and filtered. The solvent was evaporated and the residue was purified by flash chromatography (silica gel, gradient of heptane in ethyl acetate) to give the title compound as a yellow solid (20.52 g, 93%). MS (EI, m/e): 222.0 [M+].

1. addition75-89-8]) was added dropwise over a period of 20 minutes to the cold suspension
2. stirringStirring
3. waitwas continued for 10 minutes at 0° C. and for 2 hours at r.t
4. extractionwas then extracted two times with ethyl acetate
5. washThe combined organic layers were washed with brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. customThe solvent was evaporated
9. customthe residue was purified by flash chromatography (silica gel, gradient of heptane in ethyl acetate)

ORD-Eintrag

ord-79494cfcee684ca1ab5cbd7d81375975

Quelldatensatz

uspto-grants-2013_05

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08440710B2