Synthesis and herbicidal activity of novel substituted 2- and 4-pyrimidinyloxyphenoxypropionate derivatives

Abstract

Aryloxyphenoxypropionates (APPs) are a class of herbicides targeting acetyl-CoA carboxylase (ACCase) in monocot chloroplast. The article presents the rational design and synthesis of a series of APPs with 2-and 4-pyrimidinyloxy moieties. The developed synthetic protocols are versatile and allow convenient functionalization of the phenoxypropionate core with various 2-or 4-pyrimidinyl moieties via the oxygen bridge by taking advantage of the reactivity difference between 2-methylsulfonyl and 4-chloro on the pyrimidine ring. Preliminary bioassay shows that most of title compounds have good herbicidal activities against rape and barnyard grass at 100 mg/L. Several compounds are more potent to inhibit the stalk growth of barnyard grass than the commercial herbicide cyhalofop.

Synthesis and herbicidal activities of 2‐((3‐pyridinyl‐2‐oxo‐2,3‐dihydrobenzo[d]thiazol‐6‐yl)oxy)propionates

“…[19][20][21][22] Although the trend of AOPP development has decreased in the following years, investigation on the structural modification of diclofop is ongoing, and the strategy of scaffold-hopping has still been used widely in the literature. [23][24][25] In this study, our objective was to employ an unprecedented scaffold-hopping strategy by substituting the B-ring of haloxyfop with benzothiazole, thereby introducing a novel approach for structural modification of AOPPs that has not been reported previously. However, contrary to our expectations of obtaining 2-[(2-pyridinyl)oxy]benzothiazols (I), a series of 3-(2-pyridinyl)-2 (3H)-benzothiazolone derivatives were finally obtained (II) (Fig.…”

“…Other important commercial AOPPs, such as fenthiaprop, fenoxaprop, quizalofop and metamifop, were obtained by using another scaffold‐hopping approach, in which pyridine was replaced with benzothiazole, benzoxazole or quinoxaline 19–22 . Although the trend of AOPP development has decreased in the following years, investigation on the structural modification of diclofop is ongoing, and the strategy of scaffold‐hopping has still been used widely in the literature 23–25 …”