Sulfuric Acid → Diethyl (4-chloro-2-nitroanilino)methylphosphonate

Temperature

95 °C

With stirring and under a nitrogen atmosphere 4-chloro-2-nitroaniline (5 g, 28.9 mmole) was dissolved in diethylphosphite (21.44 g, 155 mmole), followed by the addition of a solution of sulfuric acid (0.1 mL) and water (0.1 mL). Under a continuous flow of nitrogen the solution was heated to 95° C., after which diethoxymethane (9.05 g, 86.8 mmole) was added in a dropwise manner over a period of 1.5 hours while maintaining the temperature between 93°-97° C. Once all the diethoxymethane was added, the reaction was kept at 95°-105° C. for another hour after which the mixture was cooled to 45°-50° C. and cold water (70 mL) was added over 20 minutes. The resulting suspension was filtered, washed first with water (10 mL), then with heptane (10 mL). The obtained orange solid was dried at 30°-40° C. for 16 hours to yield 8.85 g (95%) of the title compound, mp 94°-5° C.

1. temperaturewhile maintaining the temperature between 93°-97° C
2. waitthe reaction was kept at 95°-105° C. for another hour
3. temperatureafter which the mixture was cooled to 45°-50° C.
4. filtrationThe resulting suspension was filtered
5. washwashed first with water (10 mL)
6. customThe obtained orange solid was dried at 30°-40° C. for 16 hours

ORD record

ord-aae98600148745eb81ca288f533f5fc3

Source dataset

uspto-grants-1999_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05864040