Imidazo thiazoles 6- chloro

The hydrobromide of ( )-6-chloro-5-(2-thienylvinyl)-2,3-dihydro-imidazo[2,l- ]thiazole 127 was found to be potent as an inhibitor of mitochondrial NADH dehydrogenase becoming a preferred target of commercial pesticides, especially insecticides and acaricides <1995JME1090, 1999EJM883>. 

Combinations of N- and 5-alkylation in 2-imidazoline-2-thiols can lead to 5,6-dihydro-4//-imidazo[2,l-6]thiazoles when the heterocycles are treated with ketones in the presence of a halo-genating agent. This is a variant of the Hantzsch thiazole synthesis <92SC1293>. A further example of A-acylation in combination with nucleophilic substitution is the conversion of 2-chloro-2-imi-dazoline into (131) when it is treated with pyridine and an aryl isocyanate <87JCS(P1)1033>. 2-Imidazolines like clonidine are also known to A-nitrosate <93JCS(P2)59l>. Intramolecular alkylation is exemplified in the base-induced rearrangement of 2,5-diaryl-4-chloromethyl-2-imidazolines (132) into pyrimidines (Scheme 64) <93JOC6354>. 

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