Diethyl Ether → 2-Chloro-6-(methylthio)benzenamine

A mixture of 36.0 g (196 mmol) of 2-amino-4-chlorobenzothiazole, 108 g (2.8 mmol) of sodium hydroxide, and 480 mL of water was heated at reflux with stirring for 4.5 hours. The resulting mixture was cooled and diluted with 180 mL of water. Six drops of tetrabutylammonium hydroxide were added and then 22.5 mL (235 mmol) of dimethyl sulfate dissolved in 50 mL of toluene was added dropwise over a 20-min period with stirring. The mixture was stirred another 30 min at ambient temperature. Ether was added and the phases were separated. The aqueous phase was extracted with ether. The combined organic phase and extract were treated with dimethylamine to destroy excess dimethyl sulfate, washed with water, dried, and concentrated by evaporation under reduced pressure. The residual liquid was distilled at 1 mm (millimeter) Hg (130 Pascals) pressure and the 18 g (53 percent of theory) colorless liquid fraction boiling at 100° C. was collected and shown to be the title compound.

1. temperaturewas heated
2. temperatureat reflux
3. temperatureThe resulting mixture was cooled
4. additionwas added dropwise over a 20-min period
5. stirringwith stirring
6. stirringThe mixture was stirred another 30 min at ambient temperature
7. customthe phases were separated
8. extractionThe aqueous phase was extracted with ether
9. extractionThe combined organic phase and extract
10. additionwere treated with dimethylamine
11. customto destroy excess dimethyl sulfate
12. washwashed with water
13. customdried
14. concentrationconcentrated by evaporation under reduced pressure
15. distillationThe residual liquid was distilled at 1 mm (millimeter) Hg (130 Pascals) pressure
16. customthe 18 g (53 percent of theory) colorless liquid fraction boiling at 100° C. was collected

ORD record

ord-62e2e3f996b24a759b63cce5e9350b47

Source dataset

uspto-grants-2001_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06265606B1