thiosemicarbazone derivative article 14 proton nuclear magnetic resonance 14 unclassified drug 14 Thiosemicarbazones 10 carbon nuclear magnetic resonance 10 heterocyclic compound 10 acetylation 8 chemical structure 8 cyclization 8 priority journal 8 stereochemistry 8 structure analysis 8 X ray diffraction 6 chirality 6 drug synthesis 6 thiadiazole derivative 6 1,3,3 trimethyl 2 norcamphanone 4 3,4 dihydronaphthalen 1(2h) one thiosemicarbazone 4 3,4' dimethoxybenzophenone thiocarbamazone 4 4 methoxybenzophenone thiocarbamazone 4 4,4' dimethoxybenzophenone thiocarbamazone 4 5 acetamido 3 n acetyl 2 (3',4' dimethoxyphenyl) 2 phenyl 1,3,4 thiadiazoline 4 5 acetamido 3 n acetyl 2 (4' methoxyphenyl) 2 phenyl 1,3,4 thiadiazoline 4 5 acetamido 3 n acetyl 2,2 bis(4' methoxyphenyl) 1,3,4 thiadiazoline 4 5 acetamido 3 n acetyl 2,2 diphenyl 1,3 thiadiazoline 4 5 methoxyindan 1 one thiosemicarbazone 4 6 methoxyindan 1 one thiosemicarbazone 4 Acetylation 4 Asymmetric spiro-heterocyclic compounds 4