REGIOSELECTIVE SYNTHESIS OF 4-ALKYLQUINOLINES FROM QUINOLINE VIA 1-ETHOXYCARBONYL-1,2-DIHYDROQUINOLINE-2-PHOSPHONATES

Article abstract of DOI:10.1016/S0040-4039(00)87196-8

1-Ethoxycarbonyl-1,2-dihydroquinoline-2-phosphonates (3) were treated with n-butyllithium followed by alkyl halides to afford the corresponding 4-alkylated phosphonates (7) with complete regioselectivity in 67-97percent yields.The phosphonates (7) were converted to 4-alkylquinolines (8) in ca. 50percent yields by treatment with sodium iodide in HMPA or by alkaline hydrolysis in aqueous ethanol.