| Abstrakt: |
By means of the Hurd–Mori reaction, 2-(1,2,3-thiadiazol-4-yl)-5-methyl-thiophene was synthesized. Its bromination with N-bromosuccinimide under conditions of radical initiation leads to a labile 2-bromomethyl derivative which, in the presence of proton donors or when heated, rearranges to 2-(1,2,3-thiadiazol-4-yl)-4-bromo-5-methylthiophene. The possibility of rearrangement was confirmed by quantum chemical calculations. Chlorination of 2-(1,2,3-thiadiazol-4-yl)-5-methylthiophene with sulfuryl chloride both in the presence of AIBN and without it leads to 2-(1,2,3-thiadiazol-4-yl)-3,4-dichloro-5-methylthiophene. Intermediate products that form in the course of both processes are established and schemes of their formation are offered. Bromination of 2-(1,2,3-thiadiazol-4-yl)-4-bromo- and -3,4-dichloro-5-methylthiophenes with N-bromosuccinimide proceeds at the methyl group. Obtained bromomethyl derivatives undergo nucleophilic substitution reactions in the usual manner. [ABSTRACT FROM AUTHOR] |
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