Synthesis and characterization of novel dithiocarbamic thioanhydrides and their application for plant growth stimulant and phytotoxic activity.

In this study, nineteen thioanhydrides were synthesized from the S-acylation reaction of sodium dithiocarbamates with various acyl chlorides in chloroform at room temperature. The synthesized thioanhydrides were evaluated for their growth-stimulating and phytotoxic activities. Benzoic (1a), 4-methoxy- (1b), 4-chloro- (1c), 2-bromo- (1e), 4-fluoro- (1f.) and 4-nitrobenzoic 1H-1,2,4-triazole-1-carbothioic thioanhydrides (1 g) showed moderate to excellent growth-stimulating activity, along with this (1c) exhibited excellent phytotoxic activity, 2,4-dichlorobenzoic 1H-1,2,4-triazole-1-carbothioic thioanhydride (1d) and 2,4-dichlorobenzoic pyrrolidine-1-carbothioic thioanhydride (2b) demonstrated inhibiting and moderate phytotoxic activities. Thioanhydrides (1a-c, 1f., 1 g) exhibited excellent germination energy and germination capacity of wheat seeds: 1a 82 and 90%, 1c 80 and 84%, 1 g 82 and 90% (0.01 mg/ml); 1b, 1 g 78 and 94%, 1c 78 and 90%, 1f. 80 and 94% (0.1 mg/ml). Thioanhydride (1e) showed moderate activity, germination energy and germination capacity were 72 and 76% (0.1 mg/ml), 78 and 84% (0.01 mg/ml). Thioanhydride (1d) demonstrated activity as a growth inhibitor with germination energy, and germination capacity 54 and 58% (0.1 mg/ml), 44 and 42% (0.01 mg/ml). Thioanhydride (1c) exhibited excellent phytotoxic activity analogically to herbicide 2,4-D only on lettuce seeds. Compounds (1d and 2b) were moderately active, inhibiting the growth of lettuce and bent grass seedlings.