4-Chloroaniline → HCID 178521358, compound

4-Chloroaniline (3.2 g) was dissolved in concentrated hydrochloric acid (5.8 mL) and water (11.6 mL), and the solution was stirred for 15 minutes. Then, ice (30 g) was added thereto, an aqueous solution (4 mL) of sodium nitrite (1.8 g) was added dropwise under ice cooling, and the resulting mixture was stirred for 30 minutes. The reaction solution was returned to room temperature, and an aqueous solution (60 mL) of sodium acetate (6.2 g), and a mixed solution of dibenzoylmethane (5.7 g) in diethyl ether (20 mL)-ethanol (25 mL) were added thereto. The mixture was stirred vigorously for 3 hours. Precipitated yellow crude crystals were collected by filtration, washed with water and then dried under reduced pressure, to obtain (4-chlorophenylhydrazono)dibenzoylmethane (9.5 g) as yellow crystals. To a mixed solution of these crude crystals (9.5 g) and sodium acetate (5.1 g) in acetic acid (60 mL)-acetic anhydride (15 mL), a solution of bromine (1.3 mL) in acetic acid (8.0 mL) was slowly added dropwise under ice cooling. The mixture was stirred for 30 minutes, and then for 16 hours at room temperature. The reaction solution was poured onto ice water (200 mL), and the mixture was stirred for 1 hour. Precipitated crude crystals were collected by filtration, washed with hydrous ethanol and diethyl ether, and dried under reduced pressure, to obtain the title compound (4.4 g) as pale yellow crystals.

1. customwas returned to room temperature
2. stirringThe mixture was stirred vigorously for 3 hours
3. customPrecipitated yellow crude crystals
4. filtrationwere collected by filtration
5. washwashed with water
6. customdried under reduced pressure

ORD record

ord-67548c8a91e543cfb18ee5f7a242914a

Source dataset

uspto-grants-2013_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08546452B2