Synthesis of novel diesters as potential fuel oxygenates and surfactants of renewable origin from carbohydrate-derived 5-(chloromethyl)furfural†

Abstract

5-(Chloromethyl)furfural (CMF) has received enormous interest over the past two decades as a carbohydrate-derived platform chemical for synthesizing organic chemicals of commercial significance. This work reports a general synthetic protocol for synthesizing several known and novel mono- and diesters of CMF with potential applications as chemical intermediates, neutral surfactants, and plasticizers. The functional groups on CMF were selectively activated using relatively innocuous reagents, and the products were isolated with satisfactory yields (79–90%). The three-step process starts by oxidizing the aldehyde group into a carbonyl chloride using tert-butyl hypochlorite as a selective oxidant. The resulting carbonyl chloride was reacted with an alcohol reagent in the same pot to form the monoesters. The chloromethyl group was then reacted with the triethylammonium salt of a carboxylic acid by a nucleophilic substitution reaction to prepare the diesters. The reactions were optimized for temperature, molar ratio of reagents, and solvents. Depending on the choice of alcohol and the carboxylic acid reagents, the mono- and diester products can be made entirely biorenewable.