2-Pyridinecarboxaldehyde → HCID 22939391, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of 2-pyridinecarboxaldehyde (0.96 mL, 10 mmol, 1.0 eq.) in toluene (17 mL) was added a solution of (carbethoxyethylidene)triphenylphosphorane (6.50 g, 16.1 mmol, 1.6 eq.) in toluene (24 mL). The resulting mixture was stirred at 80° C. for 18 hours. The solvent was removed in vacuo. The residue was suspended in a minimum amount of water and DCM was added. The product was extracted with 5% HCl soln. The aq. phase was cooled down to 0° C. and was basified with solid K2CO3. The product was then extracted with DCM (2×) and the comb. org. layers were dried over MgSO4, filtered, and concentrated in vacuo. The residue was purified by flashmaster (column: 100 g, flow: 45 mL/min, 45 fractions of 45 mL, Heptane 100% to Heptane+25% AcOEt). To a solution of the resulting α,β-unsaturated ester in THF (21 mL) under N2, palladium on activated carbon (10 wt. %, 33 mg) was added. The flask was carefully evacuated and refilled with H2 (3×). The black suspension was stirred at 45° C. under an H2-atmosphere for 18 hours. The black suspension was filtered through Celite. The Celite was rinsed with THF. The filtrate was concentrated in vacuo. The residue was purified by flashmaster (column: 25 g, flow: 30 mL/min, 30 fractions of 30 mL, Heptane 100% to Heptane+AcOEt 30%) to yield (±)-2-methyl-3-pyridin-2-yl-propionic acid ethyl ester as a colorless oil.

Provenance & Evidence