2,2,2-Trifluoroethanol → Ethyl 6-((2,2,2-trifluoroethoxy)methyl)imidazo[1,2-a]pyridine-3-carboxylate

To a solution of ethyl 6-(hydroxymethyl)imidazo[1,2-a]pyridine-3-carboxylate (59) (460 mg, 2.2 mmol) and DIEA (0.78 mL, 4.4 mmol) in DCM (5 mL) was added MsCl (303 mg, 2.64 mmol). The mixture was stirred at room temperature for 10 minutes then subjected to standard aqueous work up to give a residue. The crude product was dissolved in 2,2,2-trifluoroethanol (2 mL) and was added K2CO3 (608 mg, 4.4 mmol). The reaction mixture was heated at 80° C. for 2 hours. Once complete, the reaction mixture was diluted and extracted with EtOAc. The organic layers were combined, dried over Na2SO4, filtered and concentrated to afford a residue which was purified by silica chromatography to yield ethyl 6-((2,2,2-trifluoroethoxy)methyl)imidazo[1,2-a]pyridine-3-carboxylate (97). 1H NMR (400 MHz, CDCl3) δ 9.33 (m, 1H), 8.32 (s, 1H), 7.76 (dd, J=0.8, 9.2 Hz, 1H), 7.47 (dd, J=2.0, 9.2 Hz, 1H), 4.76 (s, 2H), 4.44 (q, J=7.2 Hz, 2H), 3.92 (q, J=8.4 Hz, 2H), 1.45 (t, J=7.2 Hz, 3H). MS m/z 303.1 (M+1)+.

1. customto give a residue
2. temperatureThe reaction mixture was heated at 80° C. for 2 hours
3. additionOnce complete, the reaction mixture was diluted
4. extractionextracted with EtOAc
5. dry with materialdried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated
8. customto afford a residue which
9. customwas purified by silica chromatography

ORD record

ord-cab22aae82124a399d6315ddc6078f78

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08569283B2