2306. Cinnoline
Nomenclature
CAS number: 253-66-7
1,2-Benzodiazine; benzo[c]pyridazine; 1,2-diazanaphthalene; α-phenodiazine. C8H6N2; mol wt 130.15.
C 73.83%, H 4.65%, N 21.52%.
Description and references
First prepd by reduction of 4-chlorocinnoline: Busch, Rast, Ber. 30, 521, 524 (1897). Synthesis from methyl anthranilate: Jacobs et al., J. Am. Chem. Soc. 68, 1310 (1946); from cinnoline-4-carboxylic acid: Morley, J. Chem. Soc. 1951, 1971. Crystal and molecular structure: C. Huiszoon et al., Acta Crystallogr. 33B, 1867 (1977).
Properties
Pale yellow clusters of crystals from ligroin, mp 38°; also reported as mp 40-41° (Morley). Solvated needles from ether (contg 1 mol ether), mp 24-25°. bp0.35 114°. uv spectrum: Hearn et al., J. Chem. Soc. 1951, 3318. Geranium-like odor. Poisonous. Bitter taste resembling the taste of quinine. Must be kept under nitrogen. On exposure to air it has a tendency to liquefy and turn green. Strong base: ibid. 1949, 1356. Freely sol in the usual solvents.Derivative
Hydrochloride.C8H6N2.HCl; mol wt 166.61.
C 57.67%, H 4.23%, N 16.81%, Cl 21.28%.