Hydrochloric Acid → Acetamide, 2-(hydroxyimino)-N-phenyl-

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of chloral hydrate (59.3 g, 0.36 mol), water (700 ml), and sodium sulphate (85.8 g, 0.60 mol), was heated to 50° C. When 50° C. was reached, sequentially a mixture of 3-ethyl-aniline (40.8 g, 0.33 mol), water (700 ml) and conc. hydrochloric acid (33.6 ml) and a mixture of hydroxylamine hydrochloride (74.8 g, 1.04 mol) and water (330 ml) were added. The resulting mixture was heated to 80° C. during 30 minutes and kept for another 10 minutes at this temperature before the reaction mixture was cooled on an ice-bath. The resulting precipitate was filtered off, washed with water and dried in vacuum over P2O5 to give an isonitrosoacetanilide (36.6 g), yield 58%. The isonitrosoacetanilide (10.0 g, 0.05 mol), was added portionwise to a mixture of water (9 ml) and conc. sulphuric acid (60 ml) prewarmed to 50° C., maintaining the temperature between 50-55° C. When the addition was completed, the mixture was heated to 80° C. and kept at this temperature for 10 minutes. The reaction mixture was then cooled on an ice-bath and poured on 10-12 times the reaction volume of crushed ice. The mixture was then left standing for about one hour. The water suspension was extracted with dichloromethane which was dried and evaporated resulting in an mixture of the two analogues 4-ethyl and 6-ethyl isatins approximately 0.68:1 (7.6 g), yield 84%.

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