Ethyl Acetoacetate → HCID 66747120, compound

Participants

Reaction Steps

A solution of 5-methyl-1H-benzo[d][1,3]oxazine-2,4-dione (Example 12c) (1.36 g, 7.68 mmol), ethyl 3-oxobutanoate (1.46 mL, 11.5 mmol), and NaOH (0.046 g, 1.15 mmol) in anhydrous dioxane (10 mL) were refluxed under nitrogen for 15 hrs. The solvent was then removed under vacuum, and the residue was re-dissolved in DMF (15 mL). To this solution was added POCl3 (1.41 mL, 15.4 mmol), and the reaction mixture was stirred at room temperature for 45 minutes. The reaction was carefully quenched with ice water (150 mL), and extracted with DCM (2×75 mL). The combined organic layers were washed with brine, and dried over Na2SO4. After evaporation of the solvent, the residue was purified by chromatography on silica gel eluting with 50% EtOAc in hexanes to give the title compound as red oil (520 mg, 26%). 1H NMR (400 MHz, DMSO-d6) δ 1.36 (t, J=7.6 Hz, 3H), 2.58 (s, 3H), 2.97 (s, 3H), 4.46 (q, J=7.6 Hz, 2H), 7.51 (d, J=7.2 Hz, 1H), 7.71 (m, 1H), 7.87 (d, J=7.6 Hz, 1H). MS 264, 266 (MH+)

Provenance & Evidence