Sulfuric Acid → 7-Chloro-2-nitrosonaphthalen-1-ol

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Reaction Steps

To a solution of sodium hydroxide, 22.4 g in 1.0 liter of water, is added 100 g (0.56 mole) of the chloronaphthol (V). The mixture is stirred with slight heating until solution is complete. The solution is then cooled to -5° to 0° and treated with sodium nitrite, 40.0 g, (0.6 mole) followed by the addition of concentrated sulfuric acid (176 ml) over a 90-minute period. Ice-water (600 ml) is added periodically to prevent clumping of the solid which forms. When addition of the acid is complete, the reaction mixture is stirred for another hour at -5° to 0°. The product is filtered, washed with 4.0 liters of cold water, air-dried overnight and then dried in vacuum oven at 60° for 2.5 days. Yield: 108.6 g (93.4%) light yellow-green solid.

Provenance & Evidence