61-80-3

LIGHT BROWN TO YELLOW-BROWN POWDER

Flexin ,McNeil,US,1956

sweetener

Zoxazolamine is a centrally acting myorelaxant; formerly used as an antispasmodic and uricosuric. Used as a tool for assessing hepatic cytochrome P-450 activity in rodents.

ChEBI: Zoxazolamine is a benzoxazole.

To a solution of 106 g (0.74 mol) of 2-amino-4-chlorophenol in 500 ml of water containing 69 ml of concentrated hydrochloric acid (29.2 g, 0.8 mol) are added 60.8 g (0.8 mol) of ammonium thiocyanate. The solution is placed in an evaporating dish and heated on a steam bath for 5 hours. The solid which results is then removed from the concentrated solution by filtration, washed with a small amount of water and dried. The filtrate is placed in an evaporating dish and heated on a water bath for 2 hours. At the end of this time, the mixture is cooled, and the solid which precipitates out is removed by filtration. Both solid products are 5-chloro-2-hydroxyphenylthiourea melting at 157°C, and may be combined. The calculated N content for C 7 H 7 ClN 2 OS is 13.8; that found is 13.6.
To a solution of 10 g (0.05 mol) of 2-hydroxy-5-chlorophenylthiourea in 50 ml of methanol is added a solution of 11 g (0.04 mol) of ferric chloride hexahydrate in 50 ml of methanol. The initial purple-red color changes in a few minutes to amber. After stirring for one half hour, the solution is treated with 16.5 ml of 57% ammonium hydroxide solution (0.24 mol). A brown, flocculent precipitate of ferric sulfide appears. The mixture is then refluxed with stirring for one hour, cooled and centrifuged. The centrifugate is evaporated to dryness, and the residue is shaken with ether and water to separate the organic material from the ammonium chloride. The ether layer is extracted three times with 25 ml portions of 1 N hydrochloric acid. The acid solution is then poured into excess ammonium hydroxide, and the resulting solid collected, washed with water and dried. This gives a light tan solid melting at 183°C to 185°. The material is then dissolved in 25 ml of acetone and 50 ml of benzene are added. After treatment of the solution with activated charcoal, the light yellow solution is evaporated to 25 ml and cooled. The white crystals of 2-amino-5-chlorobenzoxazole which separate melt at 185°C to 186°C.

Muscle relaxant, Uricosuric