Pharmaceutical Intermediates

Function: The appearance of isatin is orange-red single-sided prism crystals. The melting point is 203.5°C (partial sublimation). It is easily soluble in hot ethanol, slightly soluble in ether, soluble in hot water, benzene, acetone, and soluble in alkali metal hydroxide. The solution is purple-red, turns yellow after being placed, is very weakly alkaline, and has a bitter taste.