Synthesis of the 4-chlorobenzoylthiourea compound was carried out by acylating thiourea with 4-chlorobenzoyl chloride. The 4-chlorobenzoylthiourea compound will increase the lipophilic and the electronic properties other than the lead compounds of benzoylthiourea in order to, by expectation, raise the central nervous system depressant as well. The lipophilic would affect the ability of the compounds in penetrating biological membranes, which is highly dependent on the solubility of the drug within lipid/water. Log P is the most common method used in determining the parameter value. This experiment was to mix two dissolvents (octanol and water) which are immissible. The both levels of the compounds were carefully observed by a spectrophotometer UV-Vis. From the test, the result of log P value of the 4-chlorobenzoylthiourea compound was 2.32, while the theoretical log P value of the compounds, by using the π Hansch-Fujita method is 1.62 and the f Rekker-Mannhold method is 2.225. Consequently, the result of the test shows that there is a significant difference between the progress experiment and both theoretical log P methods. Moreover, in the test of the central nervous system depressant through the potentiation test to thiopental using mice indicates that the 4-chlorobenzoylthiourea compound have potentiation effects to thiopental compared to the lead compounds of benzoylthiourea.
