5-Bromothiazole is a monobromothiazole, which can be prepared via treatment of 2,5-dibromothiazole with sodium ethoxide followed by hydrogenation over spongy nickel.
If bromothiazole is too coloured, then suspend it in dilute NaOH and steam distil it. Add NaCl to the aqueous distillate, extract it with Et2O, dry it (Na2SO4), evaporate and fractionate the residue in a vacuum. The HgCl2 salt crystallises from EtOH with m 148o (dec). [Beyerman et al. Recl Trav Chim, Pays Bas 73 330 1954, Beilstein 27 III/IV 962.]
