反应详情

温度

0 °C

Into water (500 ml), m-aminobenzenephosphonic acid (87.0 g) was suspended with stirring. To the mixture, 35% hydrochloric acid (101.3 g) was added, and the mixture was cooled to 0° C. While the solution was maintained at a temperature below 5° C., 36% sodium nitrite (105.4 g) was added dropwise to the solution. The mixture was stirred for 50 minutes to diazotize m-aminobenzenephosphonic acid. Thiourea was then added to the resulting aqueous solution, and the unreacted nitrite was removed to give a diazotized compound containing solution. On the other hand, 3-aminobenzoic acid (58.6 g) was dispersed into methanol (800 ml) and heated to 55° C. to form a solution containing a coupling compound, which was then cooled to 0° C. The diazotized compound containing solution prepared above was added dropwise while the mixture was maintained at a temperature below 5° C. After stirring the mixture at 3°-5° C. for 18 hours, the resulting precipitates were collected by filtration, washed with water to give a monoazo compound, m-(2-carboxy-4-amino-phenylazo)benzenephosphonic acid in a yield of about 125.3 g.

1. additionwas added dropwise to the solution
2. stirringThe mixture was stirred for 50 minutes
3. customthe unreacted nitrite was removed
4. customto give a diazotized compound
5. additioncontaining solution
6. temperatureheated to 55° C.
7. customto form a solution
8. additioncontaining a coupling compound, which
9. temperaturewas then cooled to 0° C
10. additionThe diazotized compound containing solution
11. customprepared
12. additionabove was added dropwise while the mixture
13. temperaturewas maintained at a temperature below 5° C
14. stirringAfter stirring the mixture at 3°-5° C. for 18 hours
15. customthe resulting precipitates
16. filtrationwere collected by filtration
17. washwashed with water