Hydrochloric Acid → 2-((5-Chloro-2-nitrophenyl)diazenyl)-6-(hydroxymethyl)-4-methoxyphenol

Temperatur

0 °C

In a 500 ml round bottom flask equipped with a magnetic stirrer was added 30.0 g (174 mmol) 5-chloro-2-nitroaniline (Aldrich), conc. HCl(aq) (J.T. Baker), 100 ml deionized water and 100 ml absolute ethanol. The suspension was cooled to 0° C. and 12.7 g (184 mmol) sodium nitrite in 50 ml water was added, dropwise over 30 minutes while keeping the reaction mixture at 0° C. The reaction mixture was stirred for an additional 1 hour. Sulfamic acid (430 mg) was added to destroy excess nitrite and the reaction mixture was stirred for an additional 20 minutes. The solids were filtered and the filtrate containing the diazonium salt was set aside and kept cold at −10° C. NaOH (34.9 g, 873 mmol) was dissolved in 100 ml water and approximately one-fourth was added to a solution of (2-hydroxy-5-methoxy-1,3-phenylene)dimethanol in 100 ml deionized water and 200 ml ethanol. The diazonium salt mixture and remaining sodium hydroxide solution were added to the reaction mixture containing the phenol derivative over a 1 hour period at 0° C. The reaction mixture was allowed to stir at 0° C. for 1 hour and ambient temperature for 2 hours. The contents were poured into 3 liters water and the pH was adjusted to 5 using 1N HCl. The resultant solid was washed with several liters of water and then vacuum dried (0.1 mm Hg) at 55° C. for 40 hours using P2O5 as drying agent to afford 28.0 g (48%) of a dark solid which was used in the next step without further purification.

1. customIn a 500 ml round bottom flask equipped with a magnetic stirrer
2. customat 0° C
3. customto destroy excess nitrite
4. stirringthe reaction mixture was stirred for an additional 20 minutes
5. filtrationThe solids were filtered
6. additionthe filtrate containing the diazonium salt
7. customkept cold at −10° C
8. additionwere added to the reaction mixture
9. stirringto stir at 0° C. for 1 hour and ambient temperature for 2 hours
10. washThe resultant solid was washed with several liters of water
11. customvacuum dried (0.1 mm Hg) at 55° C. for 40 hours
12. customas drying agent

ORD-Eintrag

ord-7fd07a8684c04c7ba4027b186ec256b4

Quelldatensatz

uspto-grants-2012_07

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08232326B2