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ChEBI: Pentoxazone is an oxazolidinone that is 1,3-oxazolidine-2,4-dione which is substituted on the nitrogen (position 3) by a 4-chloro-5-(cyclopentyloxy)-2-fluorophenyl group, and at position 5 by an isopropylidene group. A protoporphyrinogen oxidase inhibitor, it is used as a pre- and post-emergence herbicide to control weeds in rice. It has a role as an EC 1.3.3.4 (protoporphyrinogen oxidase) inhibitor, an agrochemical and a herbicide. It is an aromatic ether, a member of monochlorobenzenes, a member of monofluorobenzenes and an oxazolidinone.

Pentoxazone is commercially produced via a process that begins with the formation of the 3-(4-chloro-2-fluorophenyl)-5-isopropylidene-1,3-oxazolidine-2,4-dione core through condensation of 4-chloro-2-fluoroaniline with ethyl 2-hydroxyisobutyrate under acidic catalysis, followed by ring closure with phosgene or triphosgene in the presence of triethylamine in dichloromethane. The key N-acylation at the oxazolidinedione nitrogen uses 3-chloromethyl-1,2,4-oxadiazole under phase-transfer conditions. Final purification via crystallisation from ethanol-water yields pentoxazone.

Inhibition of protoporphyrinogen oxidase (PPO) - cell membrane disruption

Herbicide