Indigo, 6,6 -dinitro

Indigo, 6,6 -Dinitro. A dark-red powder, insol in w, si sol in ale, eth or benz, sol in hot aniline. Prepd by heating 2,4-Dinitrophenyllactic acid, methylketone with Na2 C03. Sublimes on glass surfaces, puffs off on platinum surfaces Ref Beil 24, 429 (382) [245]... 

Dinitro- and diamido-indigotin have been prepared from dinitro-isatin [33]. (Compare the Synthesis of Indigo Blue, p. 231.)i... 

Trinitro-phenols—C6H2(NOj)sOH.—Two are known (1.) Picric acid—Carbazotic acid—Trinitro-phenic acid—(NOa) in 2—4—0. It-is formed by nitrification of phenol, or of 1—2—4 or 1—2—6 dinitro-phenols, and also by the action of HKOs on indigo, silk, wool, resins, etc. It crystallizes in brilliant, yellow, rectangular plates, or in six-sided prisms it is odorless, and has an intensely bitter taste, Avhence its name (from mKpbg — bitter) it is acid in reaction sparingly soluble in water, very soluble in alcohol, other, and... 

---