Hydrochloric Acid → 2-(hydroxymethyl)-4-methoxy-6-(5-methoxy-2H-benzo[d][1,2,3]triazol-2-yl)phenol

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

In a 500 ml round bottom flask equipped with a magnetic stirrer was added 24.8 g (148 mmol) 4-methoxy-2-nitroaniline (Aldrich), conc. HCl(aq) (J.T. Baker), 150 ml water, and 150 ml absolute ethanol. The mixture was cooled to −20° C. and a solution comprised of 10.8 (156 mmol) sodium nitrite in 40 ml water was added dropwise over 30 minutes. The reaction mixture was stirred for an additional 1 hour and then sulfamic acid (315 mg) was added to destroy excess nitrite. The undissolved solids were filtered and the filtrate containing the diazonium salt was set aside and kept cold at −10° C. NaOH (29.5 g, 739 mmol) was dissolved in 100 ml water and approximately one-fourth was added to a solution comprised 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 3 hours. The contents were poured into 3 liters water and the pH was adjusted to 4.5 using 1N HCl. The resultant solid was filtered, washed with several liters of water, and then vacuum dried (0.1 mm Hg) at 65° C. for 20 hours using P2O5 as drying agent to afford 33.5 g (68%) of a dark solid which was used in the next step without further purification.

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