Yolanda Cristina Valdés Rodríguez

Alkylation of Benzoyl and Furoylthioureas as Polydentate Systems

Abstract A study of the behaviour towards alkylation of a series of benzoyl and furoylthioureas with 3,3-disubstitution has been carried out using NMR determinations. X-Ray data and semiempirical theoretical calculations demonstrated that the most stable conformation for these molecules is the so-called quasi-S. Also an explanation of the high selectivity towards the S-alkylation of these systems, based on the high contribution of the sulphur atom to the HOMO in acylthioureas is given for the title compounds. Steric factors are responsible for the difference between the percentages obtained for the S-alkylated product in 1-(4-methylbenzoyl)-3,3-diethylthiourea and 1-benzoyl-3,3-dibenzylthiourea.

Efficient Synthesis of 1-(4′-Methylbenzoyl)- 3,3-Diethylthiourea Under Microwave Irradiation Using Potassium Fluoride on Alumina

Abstract 1,1-diethylthiourea and 4-methylbenzoic acid were condensed to 1-(4′-methylbenzoyl)-3,3-diethylthiourea in open vessels under microwave irradiation using an unmodified domestic microwave oven. The synthesis was carried out in the presence of alumina impregnated with potassium fluoride and catalytic amounts of N,N-dimethylformamide. The yields are noticeably improved in comparison with classical methods.