Novel synthesis of 2,3-dihydrobenzofuran-3-amines from salicylic aldehydes: Trimethylsilyl as traceless activating group

Salicylic aldehydes were readily alkylated with (chloromethyl)trimethylsilane to give silylated ortho-methoxy benzaldehydes in 85-96 % yields. These aldehydes were converted into alkyl and aryl imines in excellent yields. O-(Trimethylsilyl)methyl moiety was applied as the synthetic equivalent of aryloxymethyl anion in the nucleophilic cyclization at the imine group promoted by CsF in DMF at 140 degrees C. Using this traceless methodology, 2,3dihydrobenzofuran-3-amines were synthesized from salicylic aldehydes in 25-55 % yields in three steps.