Diethyl (cyanomethyl)phosphonate → 1,1-Dimethylethyl cyclopropyl({2,3-dichloro-5-[(2E)-3-cyano-2-propen-1-yl]phenyl}methyl)carbamate

Participants

Reaction Steps

To a THF (0.1 M) suspension of anhydrous lithium chloride (1.2 eq.) was added sequentially diethyl(cyanomethyl)phosphonate (1.2 eq.) and DBU (1 eq.). The resulting suspension was stirred at RT for 15 min before 1,1-dimethylethyl cyclopropyl{[2,3-dichloro-5-(2-oxoethyl)phenyl]methyl}carbamate (1 eq.) from the previous step was added dropwise as a THF (0.1 M) solution. The resulting pink suspension was allowed to stir at RT for 12 h before it was carefully quenched with 1 N aq. HCl and then extracted with ether. The combined organic extracts were washed further with water and brine, dried over Na2SO4, filtered and the filtrate concentrated in vacuo. Purification of the crude product thus obtained by way of flash chromatography (SiO2, Hex→3:7 (v/v) Hex:EtOAc) afforded the title compound as a colorless oil.

Provenance & Evidence