Nomenclature
CAS number: 5103-42-4
2,2′-Dihydroxy-[2,2′-bi-1
H-indene]-1,1′,3,3′-(2
H,2′
H)-tetrone; 2,2′-dihydroxy-[2,2′-biindan]-1,1′,3,3′-tetrone; reduced ninhydrin.
C
18H
10O
6; mol wt 322.27.
C 67.08%, H 3.13%, O 29.79%.
Description and references
Formed by the action of potassium cyanide on
ninhydrin: Bruice, Richards, J. Org. Chem. 23, 145 (1958). Convenient prepn by reduction of ninhydrin
with ascorbic acid: Moore, Stein, J. Biol.
Chem. 211, 907 (1954).
Derivative
Dihydrate.
Properties
Prisms from acetone, anhydr at 100°, turns reddish-brown
at 200°, dec 249-254°. Very sparingly sol in hot water; sol in Methyl
Cellosolve. Sol with decompn in aq Na2CO3 solns
(deep red color), and in NaOH solns (deep blue color). Can be precipitated
from carbonate solns by the addn of acid. Deep purple color with
ammonia and blue color with amino acids.Use
Reagent for the photometric determination of amino
acids and similar compds.