Chain branched Cimetidine analogous thioethers, promising building blocks for the preparation of H2-histaminergic compounds, were synthetized from chiral aminoalkanethiols. Enantiomerically pure amino acids or aminoalcohols were used as starting materials. In one case, a resolution via neutral and acid di-O-(4-toluoyl)tartrates was achieved in good yields and satisfying enantiomeric excess. The absolute configuration of an ethyl branched compound was determined using X-ray diffraction and anomalous dispersion
Two isopropyl (3-methyl-1-oxo-1-((1-((4-(prop-2-yn-1-yloxy)phenyl)thio)propan-2-yl)amino)butan-2-yl)carbamate diastereomers were isolated. Fungicidal activities indicated that the isolated four chiral compounds possessed excellent activity against P. capsici with the EC50 value of 4a (1.30 μg/mL), 4b (0.078 μg/mL), 4c (1.85 μg/mL), and 4d (44.4 μg/mL). Among them, compound 4b exhibited remarkably high activities against Phytophthora capsici, which is better than that of positive control dimethomorph. Its R and S isomers showed that chiral influences the activity against P. capsici.