Reaction of α-(n-Alkylcarbonyloxy)alkyl (ACOA) Halides with 4-Hydroxy­acetanilide and 2,2,5,7,8-Pentamethyl-6-chromanol: The Effect of Steric Hindrance­ on Reaction Path

Abstract

A convenient synthesis of a-(n-alkylcarbonyloxy)alkyl (ACOA) iodides has been developed and a homologous series of nalkylcarbonyloxymethyl (ACOM) iodides have been used to alkylate 4-hydroxyacetanilide (acetaminophen, APAP), a sterically unhindered phenol, and a sterically hindered phenol (2,2,5,7,8pentamethyl-6-chromanol). Steric hindrance was not a significant factor in the ratio of acylated (Path b) to alkylated (Path a) for these reactions. Given the reported toxicity associated with sterically hindered ACOM prodrugs, n-alkyl ACOM and ACOA promoieties present themselves as viable alternatives to the more commonly used pivalate-based derivatives.