An efficient synthesis of 2,5-dihalothiazole-4-carboxylates has been described. Halogenation of aminothiazole carboxylate with NBS or NCS and subsequent diazotization with isoamyl nitrite and halogenation with CuBr2, CuCl2 or CH2I2, provided the corresponding diahalothiazole derivatives. The four-step process described is amenable to scale-up and requires 110 chromatographic purification in all the steps. (C) 2002 Published by Elsevier Science Ltd.
Soluble Head-to-Tail Regioregular Polythiazoles: Preparation, Properties, and Evidence for Chain-Growth Behavior in the Synthesis via Kumada-Coupling Polycondensation
作者:Frank Pammer、Jakob Jäger、Benjamin Rudolf、Yu Sun
DOI:10.1021/ma501213g
日期:2014.9.9
two new aryl-nickel-complexes, which furnished material with particularly lowpolydispersities (<1.4 at Mn > 100 kDa). Furthermore, a direct correlation between the obtained molecular weight and the monomer/catalyst ratio was observed in series of batch polymerization experiments, in agreement with a chain-growthpolycondensation process. The incorporation of the precatalyst–aryl moiety into the polymer
An efficient synthesis of 2,5-dihalothiazole-4-carboxylates has been described. Halogenation of aminothiazole carboxylate with NBS or NCS and subsequent diazotization with isoamyl nitrite and halogenation with CuBr2, CuCl2 or CH2I2, provided the corresponding diahalothiazole derivatives. The four-step process described is amenable to scale-up and requires 110 chromatographic purification in all the steps. (C) 2002 Published by Elsevier Science Ltd.