Diphenylacetylene → Methyl 4,5-diphenylisoxazole-3-carboxylate

Participants

Reaction Conditions

Reaction Steps

A mixture of 1,2-diphenylethyne (1.53 g, 8.6 mmol) and dimethyl 2-nitromalonate (1.05 mL, 7.83 mmol) in mesitylene (11 ml) was heated to 150° C. for 18 hr. The volatiles were removed in vacuo and the residue was chromatographed on a 5×12 cm silica gel column eluting with 0-10% EtOAc/hexanes. The essentially pure fractions containing product were concentrated to afford methyl 4,5-diphenylisoxazole-3-carboxylate (307 mg, 1.1 mmol, 14.04% yield) as a light yellow solid. HPLC retention time=1.85 minutes (YMC Combi 4.6×30 mm S-5 ODS column) eluting with 10-90% aqueous methanol+0.1 TFA a 2 minute gradient.

Provenance & Evidence