Synthesis Of Mercapto-compound

Mercapto-compounds, as an important raw metarial and pharmaceutical intermediate, consisted of mercaptan and thiolphenol. In this text, several methods were studied to synthesize the mercaptan and thiophenol.Preparing the mercaptan was starting from bromides, generated in the reaction of alcohol with NaBr.Subsequent alkylation of Bromides, followed by hydrolysis successfully afford mercaptan. The major study was focused on the synthetic technics, and the optimal conditions were determined as follows:the mole ratio of Alkyl bromidel to thiourea being 0.9:1; using 95% ethanol solution as solvent, the mixture reacted in 95% alcohol for 5h, then the solution was hydrolyzed with 20% of the alkaline for 2h. The final product was from 80% to 90%, with high purity up to 99%.Thiophenol and derivatives were prepared in stepwise, involving Grignard reaction of bromobenzen with magnesium, addition reaction of the Grignard reaction generated in situ with sulphur, followed by hydrolysis to afford the target product. The optimal synthetic technology was determined through investigating reaction temperature, reaction time as follows:First step, n (bromobenzene):n (Mg)= 1:1.1, anhydrous tetrahydrofuran as solvent with reaction temperature is 75℃for 2h and the yield of Grignard reagents is 85.9%. Second step, reaction temperature is 65℃for 40min and the yield is 72.5%. Third step, the optimize acid concentration of hydrolysis is 2.27mol/L, hydrolysis reaction temperature was 70℃for 50min and the yield of thiophenol was 64.8%.The synthesis ofβ-naphthalenethiol was completed via acylchloride ofβ-Naphthyl-sulfonic acid and deoxidize. The optimal synthetic reaction condition was n (β-naphthalene sulfonate):n (SOCI2)= 1:2.1, with DMF as solvent, acylchloride reaction time was 40℃, theβ-naphthylsulfonic chloride yield 70.7%, the final yield ofβ-naphthalenethiol was 38.4%.based on theβ-naphthylsulfonic acid.