Efficient preparation of dichloromethyl alkyl ethers and their application in the formylation of aromatic compounds: Scope and limitations.

Abstract Practical preparations of dichloromethyl alkyl ethers are described, based on the reaction of alkyl formates with oxalyl chloride in the presence of N -methylformanilide. The method involves a simple procedure that does not require the use of harmful reagents. Dichloromethyl propyl and dichloromethyl butyl ethers represent secure synthetic equivalents to dichloromethyl methyl ether. Formylations of both electron-deficient and electron-rich aromatics with these dichloromethyl alkyl ethers in the presence of AlCl 3 , FeCl 3 , or TiCl 4 have been systematically investigated. A plausible mechanism of formylation is discussed. Graphical abstract Image 1 [ABSTRACT FROM AUTHOR]