Synthesis, crystal structure, and herbicidal activity of novel 1,2,3-thiadiazole substituted 2-cyanoacrylates

2010 ARKIVOC  
A series of novel 2-cyanoacrylates containing the 1,2,3-thiadiazole ring moiety were synthesized and characterized by 1 H NMR, 13 C NMR, elemental analysis and, in one case, by X-ray crystallography. Most of these cyanoacrylates exhibited good herbicidal activities. In particular, (Z)-methoxyethyl-and (Z)-ethoxyethyl-2-cyano-3-isopropyl-3-(4-methyl-1,2,3-thiadiazol-5yl)methylaminoacrylate 9h and 9g showed 100% herbicidal activities against rape and amaranth pigweed at a dose of 1.5 kg/ha.
more » ... of 1.5 kg/ha. 2-Cyanoacrylates containing the thiadiazole ring are a new variation of this class of compound which still retain herbicidal activities. General Papers ARKIVOC 2010 (ii) 330-339 Intermediates 2-cyano-3,3-dimethylthioacrylates 8a, 8b were achieved by treating corresponding esters 7 with carbon disulfide and 2 mole of dimethyl sulfate in a one pot reaction using potassium hydroxide as alkali in good yield according to the reported methods (Scheme 2). 11 Intermediate (Z + E)-2-cyano-3-methoxyacrylates 8c-h were synthesized by treating esters 7 with the corresponding acid chloride followed by methylation with diazomethane in good yield according to the reported methods (Scheme 3). 11 Scheme 1. Synthetic route to intermediate compound 6. Scheme 2. Synthetic route to intermediates 8a and 8b. Scheme 3. Synthetic route to intermediates 8c-8h.
doi:10.3998/ark.5550190.0011.228 fatcat:quhnfohuznasrbyer7qmpbpaou