5-Aminobenzothiazole was written by Spieler, I.;Prijs, B.. And the article was included in Helvetica Chimica Acta in 1950.Electric Literature of C7H4N2O2S2 This article mentions the following:
5-Aminobenzothiazole (I) was synthesized as the HCl salt and tested for its tuberculostatic effect. 2,5-Cl(O2N)C6H3NH2 (1 g.) was refluxed 2 hrs. with 10 ml. 85% HCHO and poured into water, precipitating 0.62 g. 2,5-Cl(O2N)C6H3NHCHO (II), colorless needles, m. 179-80° (from alc.). 2,4-(O2N)2C6H3Cl (20 g.) in 40 ml. alc. was treated with 66 g. NaSH solution dropwise, stirred 1 hr., and refluxed; chilling, adding 10 g. CS2, heating to 60-70°, and refluxing 1 hr. precipitated a resinous material which was steam-distilled to remove CS2, filtered, and the filtrate acidified with HOAc to give 2-mercapto-5-nitrobenzothiazole (III), precipitated from NH3 solution by HOAc in yellow crystals, m. 223° (from PhNH2). m-O2NC6H4NH2 (5.5 g.), purified by precipitation from alc. with water, was treated in 30 ml. glacial HOAc with 6.4 g. Br, and the solution stirred, chilled with ice, and allowed to stand 2 hrs.; the HBr salt of the amine soon separated, and was filtered, dried, neutralized with NH3 water, and washed with water to give 4 g. 2,5-Br(O2N)C6H3NH2 (IV), m. 140° (from alc.). IV (3 g.) refluxed with 30 ml. 85% HCHO 3 hrs. on the water bath and poured into water precipitated 2.1 g. 2,5-Br(O2N)C6H3NHCHO (V), m. 191° (from alc.-water). To III in alc.-glacial HOAc (1:1) was added several drops 30% H2O2 with chilling; after 30 min. addition of an excess of water and ice precipitated 5-nitrobenzothiazole (VI), m. 158-9° (from alc.-water). III treated with KMnO4 and dilute H2SO4 for 15 min. at 30-35° likewise gave VI. II (1 g.) dissolved in 20 ml. alc. on the steam bath and refluxed with 500 g. Na2S 2-3 hrs. gave a deep red solution; the alc. was distilled off, the residue filtered, and the filtrate precipitated with dilute HCl to give 200 mg. yellow VI, m. 60-1°; 5 g. V similarly gave 2.1 g. VI. VI (1 g.) was reduced by treating it with excess SnCl2 in concentrated HCl, adding some Sn, and warming 0.5 hr. on a steam bath; chilling precipitated the white Sn double salt of I, m. about 210°, 5 g. of which was dissolved in 50 ml. warm water, saturated with H2S, filtered, washed, the filtrate taken to dryness, and the residue crystallized from a little water with dilute HCl to give 1.8 g. I.HCl, m. about 210°. I.HCl (3 g.) refluxed 45 min. with 2 g. molten KOAc and 12 g. Ac2O on the steam bath, then allowed to stand 1 day, taken to dryness in vacuo, the residue extracted with absolute alc., the solution again concentrated, the residue again extracted with absolute alc., the extract filtered, concentrated, and the residue recrystallized from alc.-water gave 5-acetamidobenzothiazole, m. 188-9°. In the experiment, the researchers used many compounds, for example, 5-Nitrobenzothiazole-2-thiol (cas: 58759-63-0Electric Literature of C7H4N2O2S2).
5-Nitrobenzothiazole-2-thiol (cas: 58759-63-0) belongs to thiazole derivatives. Thiazoles are a class of five-membered rings containing nitrogen and sulfur with excellent antitumor, antiviral and antibiotic activities. Electrophilic attack at nitrogen depends on the presence of electron density at nitrogen as well as the position and nature of substituent linked to the thiazole ring.Electric Literature of C7H4N2O2S2
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica