Sulphur Analogues of Indoleacetic Acid: Synthesis and Biological Activity of some Thionaphthenacetic Acids

Abstract

The thionaphthen�2�, �3-, -5-, -6�, and -7-acetic acids have been synthesized from the chlorides of the corresponding carboxylic acids by the Arndt-Eistert reaction and their plant growth-regulating activities, as indicated by their effects upon protoplasmic streaming, have been compared with those of indole-3-acetic acid (IAA) and 2,4-dichlorophenoxyacetic acid (2,4�D). The thionaphthen-3- and -7- acetic acids and IAA have similar effects upon protoplasmic streaming, while the effects of the thionaphthen-2-, -5-, and �6-acetic acids differ from those of IAA and resemble in part those of 2, 4-D.