132-89-8

Reugaril ,Farber ,Italy ,1966

ChEBI: Chlorthenoxazine is a benzoxazine.

A mixture of 4 liters chloroform and 1,050 cc ethanol was saturated with dry hydrogen chloride gas at -5°C to +5°C in a vessel having a net volume of 15 liters and provided with a stirring device, reflux cooler, gas feed line, thermometer and dropping funnel. 455 g acrolein which had been precooled to 0°C were added dropwise to the solution over a period of 1 to 2 hours while maintaining the temperature below +5°C and vigorously stirring. 1,070 g salicylamide and 1,080 g glacial acetic acid were added to the resulting solution of beta-chloropropionaldehyde acetal, thereby forming a suspension which was heated to 60°C while stirring. A clear solution was formed which was maintained at 60°C for an additional hour. The solution was allowed to cool to about 40°C and was then washed with water by passing a strong stream of water under the surface of the chloroform and continuously withdrawing the upper phase. When the water had reached a pH of 3-4, the precipitated reaction product was separated by vacuum filtration. The chloroform phase of the filtrate was evaporated under a weak vacuum and the residue was combined with the precipitate first obtained. The combined products were stirred with 2 liters of a 5% sodium hydroxide solution. The raw reaction product was then washed with water, dried and recrystallized from ethanol. The product had the melting point of 146°C to 147°C (decomposition). The yield was 1,260 g, corresponding to 76% of the theoretical yield.

Antipyretic, Analgesic