3-Phenoxymandelonitrile

3-phenoxymandelonitrile (also 3-phenoxy-α-cyanobenzyl alcohol) is an organic compound belonging to the group of cyanohydrins. It is primarily used in the synthesis of pyrethroids, a class of insecticides.

3-Phenoxymandelonitrile

Identifiers
CAS Number	61826-76-4 Y
3D model (JSmol)	Interactive image
ChemSpider	8013157
ECHA InfoCard	100.052.566
EC Number	441-070-6
PubChem CID	9837437
CompTox Dashboard (EPA)	DTXSID00885773
InChI InChI=1S/C14H11NO2/c15-10-14(16)11-5-4-8-13(9-11)17-12-6-2-1-3-7-12/h1-9,14,16H/t14-/m1/s1 Key: GXUQMKBQDGPMKZ-CQSZACIVSA-N
SMILES C1=CC=C(C=C1)OC2=CC=CC(=C2)[C@@H](C#N)O
Properties
Chemical formula	C14H11NO2
Molar mass	225.247 g·mol−1
Hazards
GHS labelling:[1]
Pictograms
Signal word	Warning
Hazard statements	H301, H317, H318, H410
Precautionary statements	P261, P264, P264+P265, P270, P272, P273, P280, P301+P316, P302+P352, P305+P354+P338, P317, P321, P330, P333+P317, P362+P364, P391, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Production

The synthesis of 3-phenoxymandelonitrile begins with the reaction of 3-phenoxybenzaldehyde with sodium cyanide and acetic anhydride in a water/dichloromethane mixture, using benzyltriethylammonium chloride as a phase transfer catalyst. This reaction initially produces the acetate, which can be hydrolyzed enzymatically with a suitable lipase to yield enantiomerically pure (S)-3-phenoxymandelonitrile through chiral resolution.^[2] The desired product can be extracted at this stage. The remaining enantiomeric acetate can undergo racemization via reaction with triethylamine in toluene or diisopropyl ether to improve yield.^[3] An alternative synthesis involves transferring a cyano group from acetone cyanohydrin to 3-phenoxybenzaldehyde. Again, enzymatic reactions through an ester can be used to produce the enantiomerically pure compound.^[4]

Use

(S)-3-Phenoxymandelonitrile serves as an important intermediate in the production of various pyrethroids, which are carboxylic acid esters incorporating the compound as an alcohol component, and are employed as insecticides.^[2][3] Notable examples within this group include deltamethrin and esfenvalerate.^[2] The presence of the 3-phenoxy group and nitriles enhances the efficacy of these compounds compared to other pyrethroids.^[5]

Deltamethrin, an ester of 3-phenoxymandelonitrile used as an insecticide