1-Nitroso-2-naphthol
If you find any inaccurate information, please let us know by providing your feedback here
This article is compiled based on the United States Pharmacopeia (USP) – 2025 Edition
Issued and maintained by the United States Pharmacopeial Convention (USP)
C10H7NO2 173.17 CAS RN: 131-91-9.—Brown to yellowish-brown powder. Insoluble in water; soluble in alcohol, in benzene, in ether, in carbon tetrachloride, and in acetic acid.
Assay: Transfer about 250 mg, previously dried over silica gel to constant weight and accurately weighed, to a glass-stoppered
ask, and dissolve in 10 mL of sodium hydroxide solution (1 in 10). Cool the solution in an ice bath, add dilute sulfuric acid (1 in 6) until a slight, permanent precipitate is formed and the solution is slightly acid, then add 3 g of potassium iodide, shake to dissolve, add 20 mL of dilute sulfuric acid (1 in 6), immediately insert the stopper in the ask, and allow to stand in the dark for 2 hours. Titrate the liberated iodine with 0.1 N sodium thiosulfate VS, adding 3 mL of starch TS as the endpoint is approached. Perform a complete blank determination, and make any necessary correction. Each mL of 0.1 N sodium thiosulfate is equivalent to 8.66 mg of C10H7NO2: not less than 95.0% is found.
Melting Range 〈741〉: between 109° and 111°.
Residue on Ignition (Reagent test): not more than 0.2%.
