1-Tert-butyl 3-ethyl 2-(6-chloropyridazin-3-yl)-2-fluoromalonate → Ethyl 2-(6-chloropyridazin-3-yl)-2-fluoroacetate
Reaction equation
[Cl:1][C:2]1[N:7]=[N:6][C:5]([C:8]([F:21])(C(OCC)=O)[C:9]([O:11][C:12](C)(C)[CH3:13])=[O:10])=[CH:4][CH:3]=1>C(O)(C(F)(F)F)=O.C(Cl)Cl>[Cl:1][C:2]1[N:7]=[N:6][C:5]([CH:8]([F:21])[C:9]([O:11][CH2:12][CH3:13])=[O:10])=[CH:4][CH:3]=1Participants
3
Procedure
A solution of 1-tert-butyl 3-ethyl 2-(6-chloropyridazin-3-yl)-2-fluoromalonate 45B (60.2 g, 189 mmol) in 300 mL TFA/DCM (1:1) was stirred at 25° C. for 2 hrs and then concentrated to dryness via rotary evaporation. The resulting residue was dissolved in EtOAc (300 mL), washed with saturated NaHCO3 solution, dried over MgSO4, and then concentrated to dryness to give the title compound, ethyl 2-(6-chloropyridazin-3-yl)-2-fluoroacetate 45C (36.6 g, 167 mmol, 89%). The material was used immediately without further purification. 1H NMR (400 MHz, DMSO-d6) δ ppm 1.18 (t, J=7.20 Hz, 3 H) 4.23 (qd, J=7.12, 4.42 Hz, 2 H) 6.43-6.62 (m, 1 H) 8.00-8.12 (m, 2 H). ESI-MS:m/z 219.0 (M+H)+.