The Pharmacology of Basic Esters of Thiazole Carboxylic Acids

During an investigation into the pharmacological properties of thiazole com- pounds, several basic esters of 4-methyl-thiazole-5-carboxylic acid (II) and the diethylaminoethyl esters of 4-methyl-thiazole-5-acetic acid (III,R = CH3), thiazole- 5-acetic acid (III,R =H) and 2-amino-4-methyl-thiazole-5-carboxylic acid (IV) were prepared (Jones, Strachan and Robinson, 1946); these have now been examined pharmacologically.The close chemical relationship between these compounds and Trasentin (I) suggested that they might possess spasmolytic properties, and this has been confirmed in vitro.The appearance, moreover, of convulsions produced by the injection of non-toxic doses of these compounds into rabbits, mice, and guinea-pigs revealed stimulant properties on the C.N.S., which have been studied.Finally, the similarity in structure of diethylaminoethyl-2amino-4-methylthiazole-5-carboxylate (IV) and procaine prompted us to investi- gate the local anaesthetic properties of this compound. 111 (C2H5)2N.CH2.CH20.CO.CH I I I R (C2H5)2N.CH2.CH20.CO.CH2.C C N I-C b CH III /CH3 R.CH2