Effect of primary amines of binuclear, noncondensed ring compounds on the growth of tubercle bacilli was written by Erlenmeyer, H.;Becker, C.;Sorkin, E.;Bloch, H.;Suter, E.. And the article was included in Helvetica Chimica Acta in 1947.Formula: C9H7NS This article mentions the following:
C.A. 41, 6925h. A systematic series of compounds similar in structure to p-H2NC6H4Ph (I), with a tertiary C atom para to the NH2 group, was prepared to test the influence of the tertiary linkage on tuberculostatic activity. The growth of tubercle bacillus in surface cultures on Lockemann medium is totally inhibited by 1-25 × 10-7 M I. In comparison with 2 × 10-4 M Na salicylate, I is 1600 times as effective in restricting the growth of tubercle bacillus in vitro, i.e., I has a salicylate number (SN) 1600. The selected compounds, 2-(p-aminophenyl)thiazole (II), 4-(p-aminophenyl)thiazole (III), 5-(p-aminophenyl)thiazole (IV), and the isoteric 3-(p-aminophenyl)pyridine (V), show total inhibition of Lockemann surface cultures at 2.5 × 10-7, 5 × 10-7, 1 × 10-7, and 3.3 × 10-7 M, resp., and have 800, 400, 2000, and 600 SN. The linkage relationship existing in I and the 3 thiazoles was demonstrated in the syntheses. The nitration of the corresponding phenylthiazoles with HNO3 and H2SO4 at 0° gave the p-NO2 derivative exclusively whereas nitration of BzOH yields only the m-NO2 compound PhCSNH2 (60 g.) and 50 g. dipolymerized BrCH2CHO in 180 cc. absolute alc. containing 3 drops of piperidine were refluxed 10 hrs. The alc.-free reaction mixture was steam-distilled in the presence of 2 N Na2CO3 and the distillate was extracted with ether. Distillation of the oil from the evaporated dried extract yielded 47 g. (72%) 2-phenylthiazole, b18 125-8°, nitrated to give 80% of the corresponding 2-(p-nitrophenyl)thiazole, m. 147-8°. Reduction with Raney Ni in absolute alc. produced 2.75 g. (75%) II, m. 123-4°; Ac derivative, C11H10N2OS, m. 140-1°; Bz derivative, C16H12N2OS, m. 164-6°. The reduction of II gave orange crystals of 4,4′-di-2-thiazolylazoxybenzene, C18H12N4OS2, m. 234-5°. Nitration of 4-phenylthiazole produced 90% of needles of 4-(p-nitrophenyl)thiazole (VI), m. 177-8°, reduced to 83% III, m. 99-100°. As proof of structure, VI was degraded by oxidation with K2Cr2O7 in H2SO4 to p-NO2C6H4CO2H in 62% yields. Bromination of 20 g. PhCH2CHO in 100 cc. absolute CHCl3 under CO2 with 10 cc. Br 6 hrs. gave 32 g. of light-green oily PhCHBrCHO, converted according to Ger. pat. 670,131 (C.A. 33, 2909.5) with HCONH2 and PS5 in toluene to 14.5% 5-phenylthiazole (VII), m. 40-1°. Nitration of 2.5 g. VII gave 2.95 g. (92%) of crude nitration product, recrystallized from alc. to yellow needles of 5-(p-nitrophenyl)thiazole (VIII), C9H6N2O2S, m. 145-6°, oxidatively degraded to p-NO2C6H4CO2H. Catalytic reduction of 3.2 g. VIII with Raney Ni and recrystallization from H2O produced 2.2 g. (80%) of colorless needles of IV, C9H8N2S, m. 149.5-50.0°; BzO derivative m. 206°. In the experiment, the researchers used many compounds, for example, 5-Phenylthiazole (cas: 1826-13-7Formula: C9H7NS).
5-Phenylthiazole (cas: 1826-13-7) belongs to thiazole derivatives. The higher aromaticity of thiazole is due to delocalization of a lone pair of sulfur electrons across the ring, which is evidenced by chemical shifts of ring hydrogen at δ 7.27 and 8.77 ppm (C2 and C4), indicating diamagnetic ring current. The pyridine-type nitrogen in the thiazole ring deactivates the ring for electrophilic substitution reactions, which is further reduced in acid due to protonation of the thiazole ring.Formula: C9H7NS
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica