Process for the preparation of enantiomerically pure pyrethroid insecticides
AssigneeSyngenta Limited
InventorsStephen Martin Brown, Brian David Gott
Life of this patent
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Abstract
A process for producing compounds of formula (VIIa) and (VIIb) wherein X is a leaving group; Y and Y1 are idependently Cl or Br; and Z is Cl, Br or a haloalkyl group which process comprises a) reacting a compound of formula (VII) wherein X, Y, Y1 and Z are as defined for compounds (VIIa) and (VIIb) with a substantially optically pure chiral amine in a solvent to form a diastereoisomeric salt; b) separating the diastereomeric salt of each enantiomer; c) converting the diastercomeric salt of each anantiomer separately to compounds of formulae (VIIa) and (VIIb) respectively by acid or base hydrolysis, the use of the compounds in making pyrethroid insecticides and novel intermediates.
Claims13
A process for producing compounds of formula (VIIa) and (VIIb)
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- wherein X is a leaving group;
- Y and Y1 are independently Cl or Br;
- and Z is Cl, Br or a haloalkyl group which process comprises
- a) reacting a compound of formula (VII)
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- wherein X, Y, Y1 and Z are as defined for compounds (VIIa) and (VIIb) with a substantially optically pure chiral amine in a solvent to form a diastereoisomeric salt;
- b) separating the diastereomeric salt of each enantiomer;
- c) converting the diastereomeric salt of each enantiomer separately to compounds of formulae (VIIa) and (VIIb) respectively by acid or base hydrolysis.
The (−) enantiomer of a compound of formula (IV) or salts thereof:
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- wherein R is H or alkyl and Y, Y1 and Z are Cl or Br.
The (+) enantiomer of a compound of formula (IV) or salts thereof:
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- wherein R is H or alkyl and Y, Y1 and Z are Cl or Br.
The (+) enantiomer of (2,3,5,6-tetrafluoro-4-methylbenzyl-(Z)-(1RS)-cis-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate.
An insecticidal acaricidal and nematicidal composition comprising an insecticidally, acaricidally or nematicidally effective amount of the (+) enantiomer of (2,3,5,6-tetrafluoro-4-methylbenzyl-(Z)-(1RS)-cis-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate.
A method of combating and controlling acarine or nematode pests at a locus which comprises treating the pests or the locus of the pests with an effective amount of the (+) enantiomer of (2,3,5,6-tetrafluoro-4-methylbenzyl-(Z)-(1RS)-cis-3-(2-chloro-3,3,3-trifluoroprop-1-enyl)-2,2-dimethylcyclopropanecarboxylate.
Dependencies are inferred from the claim text.