Toluene → alpha-Cypermethrin 1-Epimeric Mixture

HRID 647457Notes

Reaction equation

[Cl:1][C:2]([Cl:12])=[CH:3][C@@H:4]1[C@H:6]([C:7]([OH:9])=[O:8])[C:5]1([CH3:11])[CH3:10].C(=O)([O-])[O-].[K+].[K+].C1(C)C=CC=CC=1.C1(C)C=CC(S(O[CH:36]([C:50]#[N:51])[C:37]2[CH:42]=[CH:41][CH:40]=[C:39]([O:43][C:44]3[CH:49]=[CH:48][CH:47]=[CH:46][CH:45]=3)[CH:38]=2)(=O)=O)=CC=1>O.[Br-].C([N+](CCCC)(CCCC)CCCC)CCC>[Cl:1][C:2]([Cl:12])=[CH:3][C@@H:4]1[C@H:6]([C:7]([O:9][CH:36]([C:50]#[N:51])[C:37]2[CH:42]=[CH:41][CH:40]=[C:39]([O:43][C:44]3[CH:45]=[CH:46][CH:47]=[CH:48][CH:49]=3)[CH:38]=2)=[O:8])[C:5]1([CH3:10])[CH3:11]

Participants

Conditions

Temperature: 70 °C

Procedure

Cis-3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropane carboxylic acid (1680 g, 8.04 M) was added to a solution of potassium carbonate (555 g, 4.02 M) in water (3800 ml). Toluene (7600 ml), tetra-n-butylammonium bromide (115 g, 0.4 M) and alpha-cyano-3-phenoxybenzyl p-toluenesulphonate (2902 g, 7.65 M; prepared as in Example 1(A) above) were added to the stirred mixture which was then heated at 70° C. for 5 hours. The mixture was cooled to ambient temperature and the organic phase was separated off, washed twice with aqueous potassium carbonate solution and twice with water, evaporated and degassed under vacuum to leave cis-alpha-cyano-3-phenoxybenzyl 3-(2,2-dichlorovinyl)-2,2-dimethylcyclopropanecarboxylate as a yellow oil (3130 g, 99%), containing less than 1% trans-isomers.

Workup

temperatureThe mixture was cooled to ambient temperature
customthe organic phase was separated off
washwashed twice with aqueous potassium carbonate solution and twice with water
customevaporated
customdegassed under vacuum

Sources & evidence

ORD record: ord-4add32f706d6482bb574c4d3955c5caa
Source dataset: uspto-grants-1983_10
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US04409150

Reaction notes

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