Uses
Ipconazole controls a wide range of seed diseases in rice and other
crops and is particularly effective against 'Bakanae disease', Helminthosporum
leaf spot and blast on rice.
Definition
ChEBI: A member of the class of cyclopentanols carrying 1,2,4-triazol-1-ylmethyl, 4-chlorobenzyl and isopropyl substituents at positions 1, 2 and 5 respectively. Used to control a range of seed diseases in rice, vegetables and other, mainly non-food, crops.
Production Methods
Ipconazole is commercially produced via a stereoselective multi-step synthesis starting from 1-(2,4-dichlorophenyl)propan-1-one. The process involves bromination at the alpha-position, typically using bromine in acetic acid to form the alpha-bromo ketone, followed by nucleophilic substitution with 1,2,4-triazole under basic conditions to yield the triazolyl ketone intermediate. This undergoes asymmetric reduction using a chiral catalyst or chiral auxiliary to selectively produce the (2R,3S)-2-(2,4-dichlorophenyl)-3-(1H-1,2,4-triazol-1-yl)propan-2-ol stereoisomer. Final cyclisation with isopropyl methanesulfonate or isopropyl halide under phase-transfer catalysis forms the 1,3-dioxolane ring, yielding ipconazole.
Mechanism of action
Systemic, broad-spectrun, inhibits sterol synthesis in fungi.
Metabolic pathway
Ipconazole is a mixture of two geometric isomer pairs (lRS,2SR,5RS)
(I) and (lRS,2SR,5SR) (Ⅱ). They differ in the orientation of the hydroxy,
benzyl and isopropyl groups. The ratio of I : II in the technical product is
90 : 10 and the two-component isomer pairs are of equal activity. The
metabolism of ipconazole in plants and animals involves oxidation at the
benzylic and isopropyl groups to yield alcohols which may be further
oxidised to the corresponding ketones or carboxylic acids (or lactones).
The resulting array of metabolites can be expected to be stereochemically
more complex than the original isomer mixture.
Degradation
Ipconazole is stable towards hydrolysis and is thermally stable.
