Acetic Acid → 4-tert-Butyl-2-chloropyrimidine

Participants

Reaction Conditions

Reaction Steps

To a dry flask containing 2-chloropyrimidine (1.0 g, 8.7 mmol) was added anhydrous Et2O (8.7 mL) and the solution was cooled to −30° C. tBuLi (1.7 M solution in n-pentane, 5.7 mL, 9.6 mmol) was added dropwise and the reaction was held at −30° C. for 30 min. The reaction was warmed to 0° C. and stirred at that temperature for 30 min, at which time the reaction was quenched by dropwise addition of a solution of acetic acid (0.60 mL, 10.5 mmol) in THF (3 mL) and water (1 mL). The reaction was maintained at 0° C. and a solution of DDQ (2.38 g, 10.5 mmol) in THF (8.7 mL) was added. After 15 minutes, NaOH (1 M, 1 mL) and water (10 mL) were added, and the dark reaction mixture was transferred to a separatory funnel containing EtOAc (50 mL) and water (50 mL). The layers were separated and the aqueous layer was extracted once with EtOAc (50 mL). The combined organic phases were washed with saturated aqueous sodium chloride (50 mL), dried over anhydrous MgSO4, filtered and concentrated under reduced pressure. Adsorption of the oily black residue on silica, followed by chromatography on silica using a gradient solvent system of 5→30% EtOAc/hexanes furnished 4-tert-butyl-2-chloropyrimidine (1.00 g, 67%) as a pale yellow oil. 1H NMR (500 MHz, CDCl3) δ 8.49 (d, J=5.2, 1H), 7.24 (d, J=5.2, 1H), 1.33 (s, 9H).

Provenance & Evidence