4-Chlorobenzenesulfonyl chloride → 4-Chlorobenzenesulfinic acid

Temperature

0 °C

Thus, in a typical procedure, p-chlorobenzene sulfonyl chloride (24 g, 0.115 mol) was added to 250 ml H2O and the resulting suspension was cooled to 0° C. and stirred for 1 hour. Sodium sulfite (15.1 g, 0.120 mol) was then added and the reaction kept at 0° C., and a pH of 7.5 was maintained by addition of 15 percent NaOH using a pH-stat. After two hours the reaction was allowed to warm to 25° C. and stirred for an additional five hours. The resulting clear solution was filtered, the filtrate cooled to 0° C. and 12N HCl at 0° C. was added to the filtrate. The resulting precipitate was collected by filtration and dried under vacuum, to give p-chlorobenzenesulfinic acid as a white solid, 17.3 g (85 percent) mp 94°-96° C. (lit 93°-96° C.). The salt was generated by slurrying the acid in an EtOH/NaOH solution containing an excess of base. The sodium salt was purified by recrystallization from EtOH. Other metal sulfinate catalysts useful according to the present invention are similarly prepared.

1. customkept at 0° C.
2. waitAfter two hours the reaction was allowed
3. temperatureto warm to 25° C.
4. stirringstirred for an additional five hours
5. filtrationThe resulting clear solution was filtered
6. temperaturethe filtrate cooled to 0° C.
7. addition12N HCl at 0° C. was added to the filtrate
8. filtrationThe resulting precipitate was collected by filtration
9. customdried under vacuum

ORD record

ord-6fb756a493124dc7b3dd7927977318a0

Source dataset

uspto-grants-1985_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04500468