Thiazole derivatives imidazolyl

Similarly, Boyd and co-workers at the R. W. Johnson Pharmaceutical Research Institute used this reaction for the synthesis of several imidazolyl thiazole derivatives to study significant R2A/D adrenoceptor binding affinity and in vivo anti-nociceptive activity in mice as part of a program to develop analgesic agents. 

The lactamization of A-(5,5-diphenyl-4-oxo-2-imidazolyl)glycine 41 to 6,6-diphenyl-l,6-dihydroimidazo[l,2-tf] imidazole-3,5-dione 42 (Scheme 28) and the conversion of 2-thioacetic acid derivative 43 into the respective imidazo[2,l-A thiazole-3,5-dione 44 can be induced by treatment with DCG or acetic anhydride (Schemes 28 and 29) C1997AP85, 2000PHA429, 2001JST(597)73, CHEC-III(11.04.9.1.4)159>. 

The 1,3-azoles are quatemised easily at the imine nitrogen with alkyl halides the relative rates are 1-methylimidazole thiazole oxazole, 900 15 1." In the case of imidazoles which have an A -hydrogen, the immediate product is a pro-tonated N-alkylimidazole this can lose its proton to unreacted imidazole and react a second time, meaning that reactions with alkyl halides give a mixture of imidazolium, 1-alkylimidazolium and 1,3-dialkylimidazolium salts. Furthermore, an unsymmetrically-substituted imidazole can give two isomeric 1-alkyl derivatives. The use of a limited amount of the alkylating agent, or reaction in basic solution, when it is the imidazolyl anion (section 21.4.1) which is alkylated, can minimise these complications. 

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