4-(4-Chlorophenyl)butyric acid → 7-Chloro-1,2,3,4-tetrahydronaphthalen-1-one

4-(4-Chlorophenyl)butyric acid (26.62 g) was added to 150 g of hot polyphosphoric acid (90° C.); the mixture was maintained at 90°-95° C. for 0.33 hour. After cooling to room temperature, the reaction mixture was added to 400 mL of ice-cold stirred water. The solution was allowed to warm to room temperature; and the resulting precipitate was filtered, washed (water) and air dried to give a pale yellow solid (22.3 g). The solid was recrystallized from toluene (50 mL) at -10° C. The crystals were collected and washed with cold toluene and then hexanes to give the tetralone as pale yellow crystals (18.18 g); mp 100.3°-101.1° C.

1. temperaturethe mixture was maintained at 90°-95° C. for 0.33 hour
2. temperatureto warm to room temperature
3. filtrationand the resulting precipitate was filtered
4. washwashed (water) and air
5. customdried

ORD record

ord-8875abc04b9b4289869358a3fef76b8f

Source dataset

uspto-grants-1998_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05712272