Dimethyl nitromalonate → Methyl 4-cyclopropyl-5-phenylisoxazole-3-carboxylate

Beteiligte Stoffe

Reaktionsschritte

A solution of (cyclopropylethynyl)benzene (300 mg, 2.110 mmol) and dimethyl nitromalonate (0.854 mL, 6.33 mmol) in mesitylene (4 mL) was heated to 150° C. for 16 h. The reaction mixture was concentrated to yield a crude product which was purified by silica gel chromatography with hexanes/ethyl acetate (10/1) to yield methyl 4-cyclopropyl-5-phenylisoxazole-3-carboxylate. The compound was re-purified by preparative HPLC [Column: PHENOMENEX® S10 30×100 mm; Gradient time: 10 min; Flow rate=40 ml/min; Solvent A=10% MeOH−90% Water−0.1% TFA; Solvent B=90% MeOH−10% water−0.1% TFA; Start % B=20; Final % B=100] to yield methyl 4-cyclopropyl-5-phenylisoxazole-3-carboxylate (170 mg). The compound had an HPLC ret. time=2.77 min.−Column. YMC S5 COMBISCREEN® 4.6×50 mm; Gradient time: 4 min; Flow rate=4 ml/min; Solvent A=10% MeOH−90% Water−0.2% H3PO4; Solvent B=90% MeOH−10% water−0.2% H3PO4; Start % B=0; Final % B=100. LC-MS: M+1=244+.

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