The invention belongs to the technical field of
chemical synthesis, and specifically relates to a synthesis method of
tamsulosin hydrochloride. According to the synthesis method,
benzene sulfonic
amide shown as a formula (II) and
bromine ether shown as a formula (III) are in a
condensation reaction in an aprotic polar
solvent in the presence of an acid-binding agent to generate a condensation compound intermediate shown as a formula (IV); the condensation compound intermediate is in
organic solvent, in the presence of a catalyst,
hydrogen is introduced into the
organic solvent under certain pressure so as to hydrogenate the condensation compound intermediate, then, the R-
tamsulosin free alkali shown as a formula (V) is obtained, and the R-
tamsulosin free alkali further is subjected to a
salt formation reaction with
hydrochloric acid in an
organic solvent C to produce the
tamsulosin hydrochloride shown as a formula (I). In the reaction process for preparing the
tamsulosin hydrochloride through the synthetic
route provided by the invention, the phenomenon that bimolecular
bromide and amine react with each other to generate a disubstituted by-product is avoided, and the obtained
tamsulosin hydrochloride has high product purity and high yield; according to the synthesis method, the
reaction conditions are moderate, and synthesis is convenient to finish.