Molecules, Vol. 24, Pages 3391: Isothioureas, Ureas, and Their N-Methyl Amides from 2-Aminobenzothiazole and Chiral Amino Acids
Molecules, Vol. 24, Pages 3391: Isothioureas, Ureas, and Their N-Methyl Amides from 2-Aminobenzothiazole and Chiral Amino Acids
Molecules doi: 10.3390/molecules24183391
Authors:
Itzia I. Padilla-Martínez
José Miguel González-Encarnación
Efrén V. García-Báez
Alejandro Cruz
Ángel Andrés Ramos-Organillo
In this investigation, the reaction of 2-dithiomethylcarboimidatebenzothiazole with a series of six chiral amino-acids was studied. The reaction proceeds through the isolable sodium salt of SMe-isothiourea carboxylates as intermediates, whose reaction with methyl iodide in stirring DMF as solvent affords SMe-isothiourea methyl esters. The presence of water in the reaction leads to the corresponding urea carboxylates as isolable intermediates, whose methyl esters were obtained. Finally, the urea N-methyl amide derivatives were isolated when SMe-isothiourea or urea methyl esters were reacted with methylamine in the presence of water. The structures of synthesized compounds were established by 1H and 13C nuclear magnetic resonance and the structures of SMe-isothiourea methyl esters derived from (l)-glycine, (l)-alanine, (l)-phenylglycine, and (l)-leucine, by X-ray diffraction analysis. This methodology allows to functionalize 2-aminobenzothiazole with SMe-isothiourea, urea, and methylamide groups derived from chiral amino acids to get benzothiazole derivatives containing coordination sites and hydrogen bonding groups. Further research on the biological activ...
Source: Molecules - Category: Chemistry Authors: Itzia I. Padilla-Mart ínez Jos é Miguel González-Encarnación Efr én V. García-Báez Alejandro Cruz Ángel Andrés Ramos-Organillo Tags: Article Source Type: research