Haasen and Fosdick2 reported the synthesis of several alkyl esters of#-aminothiobenzoic acid and of@-diethylamino-ethyl 9-aminothiobenzoate which they named Thiocaine. Karjala and McElvain3 reported the synthesis of 2-methylpiperidinopropylthiol-and-thionbenzoates. All these compounds were reported as efficient tocal anesthetics, so it was thought that further work an thioprocaine homologs would be interesting.
![p-Aminothiobenzoic acid S-[3-(dibutylamino)propyl] ester Structure](https://image.chemsrc.com/caspic/244/63917-80-6.png)