Synthesis of 5-arylthiazole derivatives by a ring closure of thioformamido ketones was written by Ohta, Masaki. And the article was included in Yakugaku Zasshi in 1951.Recommanded Product: 1826-13-7 This article mentions the following:
KOH (23 g.) in 80 mL. MeOH is divided into 2 portions, one of which is saturated with H2S and the other poured into it, heated to 50°, the mixture treated with 15 g. CHCl3 through the reflux condenser, let stand l0 min., filtered, and the MeOH removed in vacuo, yielding 30% HCS2K (I). Treating 5 g. BzCH2NH2.HCl in 50 mL. water with aqueous I (prepared from 23 g. KOH) 1 h. at room temperature, filtering, and washing with water gives 4.7 g. (95%) HCSNHCH2Bz (II), needles, m. 108°. II (1.2 g.) in 3 mL. concentrated H2SO4 into water after 30 min., neutralized with NH4OH, and steam-distilled gives 1 g. 5-phenylthiazole (III), m. 45-6°; picrate, decompose 136-7°. III (10 g.) in 40 mL. concentrated H2SO4 treated with 24 mL. concentrated H2SO4 and 16 mL. fuming HNO2 with cooling to 0°, poured in water, filtered, and washed with water gives 12 g. 5-(p-nitrophenyl)thiazole (IV), m. 145-6°. Reduction of 5 g. IV in a 15 mL. water, containing 2 g. NH4Cl and 20 g. Fe 2 h. at 80° gives 2 g. 5-(p-aminophenyl)thiazole (V), m. 149°. Decylamine-HCl (2 g.) and aqueous I (from 8 g. KOH) give 1.8 g. N-thioformyldecylamine (VI), m. 172°. VI (0.5 g.) in 8 g. concentrated H2SO4 poured into water gives 0.3 g. 4, 5-diphenylthiazole, m. 63-4°. m-O2NC6H4COCH2NH2.HCl (0.7 g.) in 20 mL. water and aqueous I (from 2.3 g. KOH) give 0.5 g. m-nitro-α-thioformamidoacetophenone (VII), decompose 159-60°. Treating VII with concentrated H2SO4 as in the preparation of III gives 5-(m-nitrophenyl)thiazole, m. 59°. p-ClC6H4COCH2NH2.HCl (3 g.) and aqueous I (from 12 g. KOH) give 1.5 g. HCSNHCH2COC6H4Cl (VIII), decompose 147°; treating VIII with concentrated H2SO4 as in the preparation of III gives 5-(p-chlorophenyl)thiazole, m. 40°; picrate, decompose 168°. In the experiment, the researchers used many compounds, for example, 5-Phenylthiazole (cas: 1826-13-7Recommanded Product: 1826-13-7).
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 nitrogen in thiazole is sp2 hybridized and the lone pair of electrons localized on the nitrogen is less reactive due to increased aromatic character and decreased basicity. It is protonated and alkylated/acylated at nitrogen forming hydrochloride and quaternary thiazolium salt.Recommanded Product: 1826-13-7
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica