8-Nitrocinchoninic acids and related substances was written by Buchman, Edwin R.;McCloskey, Chester M.;Seneker, J. Albert. And the article was included in Journal of the American Chemical Society in 1947.HPLC of Formula: 112656-95-8 This article mentions the following:
Tech. lepidine (650 g.), nitrated at 0-3°, gives 372 g. (48.2%) 8-nitrolepidine (I), m. 126-6.5° absorption maximum at 283, 314 mμ, and 112 g. (13.3%) of an isomer, light yellow, m. 127.5-9°, absorption maximum at 222, 278, and 316 mμ. Details are given of the oxidation of 200 g. I through the aldehyde to 160 g. crude 8-nitrocinchoninic acid (absorption maximum at 224, 293-6 mμ); Et ester (II) m. 84-5° absorption maximum at 226, 304 mμ (44% based on I). Catalytic reduction of II in EtOH over Pt oxide gives 91% Et 8-aminocinchoninate (III), red-orange, m. 77.5-8° absorption maximum at 267, 330, 400-1 mμ; free acid, dark red, m. 280-1° (rapid heating), absorption maximum at 262, 380 mμ (not reproducible); HCl salt, sparingly soluble in cold H2O. III and BzCl in C5H5N give 96% of the Bz derivative, m. 194-4.5° absorption maximum at 255, 334, and 348 mμ. α-Isonitroso-o-nitroacetanilide (preparation in 47.8% yield from o-O2NC6H4NH2, given) and concentrated H2SO4 give 68% 7-nitroisatin (IV). PhAc (18 ml.), 15.6 g. IV, and 80 ml. concentrated NH4OH, heated 8 hrs. at 130° give 87% 2-phenyl-8-nitrocinchoninamide (V), m. 274.5-5°, absorption maximum at 266-7, 340-3 mμ. V (0.5 g.) in 2 ml. concentrated H2SO4, heated 3 hrs. at 145° and the solution refluxed 4 hrs. with 20 ml. EtOH, gives 31% Et 2-phenyl-8-nitrocinchoninate (VI), m. 143-3.5° absorption maximum at 268, 347 mμ; VI was also prepared in 34.2% yield by the Doebner reaction (using o-O2NC6H4NH2, BzH, AcCO2H, and concentrated H2SO4); the effect of varying the quantities of H2SO4 and AcCO2H on the yield was studied. Reduction of VI in MeOH over Pt oxide gives 88% Et 2-phenyl-8-aminocinchoninate, m. 69-9.5° absorption maximum at 231-2, 297, 343-8, and 400-20 mμ. The 8-HO analog, yellow, m. 71-1.5° absorption maximum at 283-5, 347-8 mμ. 2,4-O2N-(MeO)C6H3NH2 (21 g.), 13.25 g. BzH, and 12.5 ml. AcOH, treated with 7 ml. concentrated H2SO4 and, after 5 min., with 11 g. AcCO2H, and heated on the steam bath 30 min., give 23% Et 2-phenyl-6-methoxy-8-nitrocinchoninate, pale yellow, m. 160-5°, absorption maximum at 264-6, 372-3 mμ; the 8-NH2 analog, red, m. 120-20.5°, absorption maximum at 299-302, 410-12 mμ, 96% yield. In the experiment, the researchers used many compounds, for example, 7-Nitroindoline-2,3-dione (cas: 112656-95-8HPLC of Formula: 112656-95-8).
7-Nitroindoline-2,3-dione (cas: 112656-95-8) belongs to indole derivatives. Indole is an important structural motif of various drugs, therapeutic leads besides its prevalence in numerous natural products, agrochemicals, perfumery, and dyes. More than 200 indole derivatives have already been marketed as drugs or are under advanced stages of clinical trials.HPLC of Formula: 112656-95-8
Referemce:
Indole alkaloid derivatives as building blocks of natural products from Bacillus thuringiensis and Bacillus velezensis and their antibacterial and antifungal activity study,
Preparation of Indole Containing Building Blocks for the Regiospecific Construction of Indole Appended Pyrazoles and Pyrroles