Sulfuric Acid → 3-Oxo-1,3-dihydro-2,1-benzoxazole-5,7-dicarboxylic acid

Beteiligte Stoffe

Reaktionsschritte

To a stirred solution of 12.8 g. of nitrotrimesic acid (prepared by alkaline potassium permanganate oxidation of nitromesitylene) in 200 ml. of water containing 30 g. of sulfuric acid are added 6.5 g. of zinc dust in portions at such a rate so as to maintain a temperature of about 25° C. After the addition, the mixture is stirred for an additional 1 hr. After this time, 200 ml. of ethyl acetate are added and the mixture is rapidly stirred for 15 min. The reaction is then filtered by suction through a pad of filter aid. The organic layer is separated, dried and concentrated under reduced pressure, leaving 9.6 g. of crude product which is used directly in the next step. ##STR16##

Herkunft & Nachweise