8049. Quinaldine Red

Nomenclature

CAS number: 117-92-0
2-[2-[4-(Dimethylamino)phenyl]ethenyl]-1-ethylquinolinium iodide; 2-[p-(dimethylamino)styryl]-1-ethylquinolinium iodide; 2-(p-dimethylaminostyryl)quinoline ethiodide; α-(p-dimethylaminophenylethylene)quinoline ethiodide; Eastman no. 1361.
C21H23IN2; mol wt 430.33.
C 58.61%, H 5.39%, I 29.49%, N 6.51%.

Description and references

Prepd by condensing quinaldine ethyliodide and p-dimethylaminobenzaldehyde in alc in the presence of piperidine: K"onig, J. Prakt. Chem. [2] 86, 172 (1912); DE 294744; Frdl. 14, 735.

Chemical structure

Properties

Very dark red powder. Sparingly sol in water. Freely sol in alcohol, giving a dark red soln. Solns are slowly dec by light. pKb 11.25. Colorless at pH 1.4; red at pH 3.2. In the presence of chlorides the transition interval is from pH 1.2 to pH 3.0.

Use

As an indicator.