The rates of reaction of α-halo ketones with thiosemicarbazides was written by Okamiya, Jiro. And the article was included in Nippon Kagaku Zasshi in 1962.Recommanded Product: 4,5-Diphenylthiazol-2-amine This article mentions the following:
The rates of reaction of phenacyl bromides with thiosemicarbazides were determined by conductivity measurement in EtOH. The reaction is second order up to 85% completion; the rate constant is obtained. The activation energies are 10.511.3 kcal./mole for the reaction of H2NCSNHNHPh (I) and 8.5-9.3 kcal./mole for H2NCSNHNH2 (II). The activation energy for the reaction between PhC(:NOH)CH2Br and NH2CSNH2 (III) or II is obtained as 10.2 or 6.6 kcal./mole. Thus, the reaction rate is shown as III > II > I and the reaction of oximes is much slower than that of the parent α-halo ketone itself. Hammett’s rule is applicable to the reaction and p is obtained as 0.63 and 0.74 for I and II, resp. The reaction products, 2-amino-5-(p-aminophenyl)thiazoles were prepared Bromomethyl ketone (0.003 mole), 0.003 mole I, and 20 cc. EtOH were heated 2 hrs., heated 30 min. after addition of 1 cc. HCl, 50 cc. H2O added, and the mixture filtered after boiling and basified with NH3 to give 55-90% yield. Methyl ketone, iodine, and I were heated 8 hrs. and treated similarly to give 40-70% yield. Thus, the following 4-substituted 2-amino-5(p-aminophenyl)thiazoles (IV) are obtained (R and m. p. given): H, 204°; Ph, 200-1°; p-MeC6H4, 190°; o-MeC6H4,210°; p-MeOC6H4, 237°; p-ClC6H4, 224°; p-BrC6H4, 247°; m-BrC6H4, 213-14°; m-IC6H4, 261°; m-IC6H4, 195°; m-O2NC6H4, 252°; m-O2NC6H4, 231°; o-O2NC6H4, 241°; p-H2NC6H4, 111° and 223° (double m.p.); p-PhC6H4, 237°; α-C100H7, 155°. KOH (5 g.) in 5 cc. H2O was saturated with H2S and 5 g. PhCOCHBrPh in 10 cc. EtOH added to give 2.5 g. PhCOCH2Ph (V) after 2 hrs. heating. PhCOCHClPh (1.1 g.) in EtOH and III EtOH were mixed and heated 2 hrs. with 3.5 cc. 3N NaOH after standing 3 hrs. to give 0.1 g. V and 0.8 g. 2-amino-4,5diphenylthiazole, m. 188°. In the experiment, the researchers used many compounds, for example, 4,5-Diphenylthiazol-2-amine (cas: 6318-74-7Recommanded Product: 4,5-Diphenylthiazol-2-amine).
4,5-Diphenylthiazol-2-amine (cas: 6318-74-7) belongs to thiazole derivatives. Thiazole rings are planar and aromatic. Thiazoles are characterized by larger pi-electron delocalization than the corresponding oxazoles and have therefore greater aromaticity. Various laboratory methods exist for the organic synthesis of thiazoles. Prominent is the Hantzsch thiazole synthesis is a reaction between haloketones and thioamides.Recommanded Product: 4,5-Diphenylthiazol-2-amine
Referemce:
Thiazole | C3H3NS – PubChem,
Thiazole | chemical compound | Britannica