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

Synthesis of 4-Bromoisatin (K-98) and 6-Bromoisatin (K-99). To a solution chloral hydride (50.0 g, 0.247 mol) in water (237 mL) were successively added Na2SO4 (69.0 g, 0.486 mol), 3-bromoaniline (40.0 g, 0.233 mol) in a mixture of 37% HCl (25 ml, 0.302 mol) and water (632 ml) with vigorous stirring. After the addition was completed, the resulting reaction mixture was heated to reflux for 10 min, and allowed to cool to room temperature. The precipitate formed was collected by filtration, washed with water (3×100 ml) and dried in vacuo to yield the crude isonitrosoacetanilide. This product was added portion-wise to rapidly stirred concentrated H2SO4 (790 ml) at a rate to keep the reaction temperature between 50 and 70° C. The reaction mixture was heated to 80° C. for 20 min and allowed to cool to room temperature. The cooled mixture was poured into crushed ice (ca. 3200 g). The mixture was allowed to stand for 1 h. The orange precipitate was collected by a filtration, washed with water and dried to yield a mixture of 4-bromoisatin (K-98) and 6-bromoisatin (K-99) (40 g, 83%). MS (ESI+): 227 (M+1). 1H-NMR (DMSO-d6)

1. additionAfter the addition
2. customthe resulting reaction mixture
3. temperaturewas heated
4. temperatureto reflux for 10 min
5. customThe precipitate formed
6. filtrationwas collected by filtration
7. washwashed with water (3×100 ml)
8. customdried in vacuo

ORD record

ord-4925d31c9c394cc9910ead36443ff7bd

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07714017B2