5-(2-Methoxy-4-nitrophenyl)oxazole → 3-Methoxy-4-(oxazol-5-yl)aniline

Participants

Reaction Conditions

Reaction Steps

Compound 2f (50 g, 1.0 eq., Nippon Soda) and 1% Pt, 2% V on C (2.78 g, 64% wet, 2.0 wt % on a dry basis, Degussa Type CF1082) were charged to a hydrogenation vessel under nitrogen. Ethyl acetate (500 ml, 10 vol) was added and the mixture was heated to 60° C. The vessel was pressurized with hydrogen (1.00 bar overpressure) and the mixture was stirred at 60° C. The reaction was complete within 3 hours. The pressure was released and nitrogen was bubbled through the reaction mixture. The reaction mixture was filtered through Celite® and washed with EtOAc (100 ml, 2 vol). The solvent level was reduced to 4 vol by distillation at reduced pressure and toluene (500 ml, 10 vol) was charged into the vessel. The solvent level was reduced to 4 vol by distillation at reduced pressure and a second portion of toluene (500 ml, 10 vol) was charged into the vessel. The solvent level was reduced to 5 vol under reduced pressure then the mixture was heated to 90° C. at atmospheric pressure to dissolve any solids. The solution was then cooled slowly to 20° C. to induce crystallization. The resulting yellow solid was filtered and washed with toluene (100 ml, 2 vol) to give compound 2g which was dried in a vacuum oven at 50° C. with a nitrogen bleed until a constant weight of 39.4 g (91%) was achieved.

Provenance & Evidence