Diisopropylethylamine → 3-(2,3-Dihydro-2,2,4-trimethylbenzofuran-7-yl)-5-(methylamino)-1,3,4-oxadiazol-2(3H)-one

Participants

Reaction Steps

A solution of 3.0 g of 3, 75 ml of methanol and 1.3 g of N,N-diisopropyl-N-ethylamine was warmed on a steam bath for 18 hours. The solvent was evaporated under reduced pressure, the residue was mixed with 75 ml of water and the mixture was extracted with ether. The extract was dried (MgSO4) and the solvent was evaporated under reduced pressure. The residue was flash-chromatographed over silica gel, using a 2:15:33 v:v:v mixture of THF, ethyl acetate and hexane as eluent. Two products were obtained: one, a light amber syrup, Rf=0.49, was identified as 3; the second, a solid (Rf=0.24) was recrystallized from ether to give 4, as a colorless solid, m.p.: 183°-184° C.

Provenance & Evidence