Pyridine → 5-(2-Methoxyethylsulfonamido)-2-methylbenzoxazole

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Into a 1.0 L round bottom flask equipped with mechanical stirrer, addition funnel, thermometer and nitrogen inlet tube was placed 100 grams (0.67 Mol) of 5-amino-2-methylbenzoxazole and 350 mL of pyridine. The slurry was stirred in an ice/ethanol bath at 0° C. then 110 grams (0.69 Mol) of Intermediate 1 was added dropwise so as to maintain a reaction temperature below 7° C. The reaction was stirred at 0° C. for two hours then the resulting red colored mixture was poured into 1.0 L of ethyl acetate. The slurry was stirred for 30 minutes then filtered and the collected solids were discarded. The filtrate was extracted with 4×200 mL of 10% hydrochloric acid and the organic phase was collected and dried over magnesium sulfate. The solvents were removed in vacuo to afford 140 grams (0.52 Mol, 76.7% yield) of desired product as a tan solid.

Herkunft & Nachweise