Thionyl Chloride → 6-[(4-Fluorophenyl)oxy]-3-pyridinecarbonyl chloride

Participants

Reaction Steps

6-[(4-Fluorophenyl)oxy]-3-pyridinecarboxylic acid (D14) (0.232 g, 0.994 mmol) was dissolved in 1,4-dioxane (6 mL) and thionyl chloride (0.363 mL, 4.972 mmol) added dropwise. The mixture was heated at reflux for 3.5 h, then cooled and concentrated in vacuo. DCM was added to the residue which was then re-concentrated to yield 6-[(4-fluorophenyl)oxy]-3-pyridinecarbonyl chloride as a yellow oil (0.252 g) which was used directly in step 2. Step 2: The acid chloride from step 1 was taken up in DCM (3 mL) and added to 1,1-dimethylethyl (2S)-2-methyl-4-{[4-(methylamino)phenyl]methyl}-1-piperazinecarboxylate (D3) (0.288 g, 0.904 mmol) in DCM (3 mL). Triethylamine (0.251 mL, 1.808 mmol) was added and the mixture was stirred at room temperature overnight. The reaction mixture was diluted with DCM and washed with water. The aqueous was extracted with DCM (×2) and the combined organic layers were dried and concentrated. The crude product was purified by column chromatography. Elution with a 0-50% EtOAc/petroleum ether gradient gave the title compound as a colourless oil (0.518 g). δH (CDCl3, 400 MHz) 8.07 (1H, m), 7.65 (1H, dd), 7.24 (2H, d), 7.03 (6H, m), 6.70 (1H, d), 4.18 (1H, br.s), 3.80 (1H, d), 3.48 (3H, s), 3.46 (1H, d), 3.34 (1H, d), 3.08 (1H, td), 2.70 (1H, d), 2.50 (1H, d), 2.10 (1H, dd), 2.00 (1H, m), 1.46 (9H, s), 1.20 (3H, d). MS (ES): MH+ 535.3. Description 16: Alternative Method (A)

Provenance & Evidence