AMIDINOETHYLATION - A NEW REACTION - IV; THE AMIDINOETHYLATION OF ALCOHOLS: A FACILE SYNTHESIS OF 3-ALKOXY-N,N'-SUBSTITUTED-PROPANAMIDINES

Article abstract of DOI:10.1016/S0040-4020(01)92362-2

The amidinoethylation of alcohols takes place by the addition of sodium alkoxides 2 (R¹=Me, Et) to the C=C double bond of a variety of N,N'-substituted-propenamidines 1 (Method A).This illustrates the activation of the C=C double bond by the conjugated amidine function and provides a new class of Michael acceptors for alcohols.However, this activation is poorer than with other nucleophiles or Michael acceptors.The amidinoethylation makes available 3-alkoxy-N,N'-substituted-amidines not easily accessible by other classical methods.However, it is demonstrated that the general N,N'-substituted-amidine synthesis via the nitrilium salts can also apply to nitrile compounds having an alkoxy group present on the molecule (method B).Since the cyanoethylation of alcohols (4) is a very fast and facile reaction the method B is the preferred strategy for the synthesis of 3-alkoxy-N,N'-substituted-propanamidines 3.