An environmentally friendly acylation reaction of 2-methylnaphthalene in solvent-free condition in a micro-channel reactor

Abstract

An efficient and solvent-free acylation of 2-methylnaphthalene (2-MN) is presented using acid chloride as both the acylating agent and solvent in a micro channel reactor. The effect of the catalyst, reactant ratio, mixing temperature, reaction temperature and reaction time on the product yield and selectivity was investigated. At room temperature with a reaction time of only 15 min, the target product, 2-methyl-6-propionylnaphthalene (2,6-MPN), was obtained in 72.3% yield with 73.8% selectivity, and 2-methyl-6-acetylnaphthalene (2,6-MAN) was obtained in 54.1% yield with 55.4% selectivity. The route of synthesis provides a more environmentally friendly and efficient method to prepare 2,6-MPN with no other toxic solvents and efficient mass transfer and heat transfer.

A greatly improved procedure for the synthesis of an antibiotic-drug candidate 2,4-diacetylphloroglucinol over silica sulphuric acid catalyst: multivariate optimisation and environmental assessment protocol comparison by metrics

“…Thereby, it must be miscible with phloroglucinol, where the molecular movement and the contact between the reactants with higher concentrations is favoured and the yield of DAPG is improved. 29,57,58 Hence, Green Chemistry principle 5, which states that the "use of solvents should be made unnecessary wherever possible and innocuous when used", is successfully implemented. 23 A plausible mechanism for the synthesis of DAPG using SSA We herein also propose a possible mechanism reaction (Scheme 4) for the ultrasound-promoted one-pot synthesis of DAPG from phloroglucinol and acetic anhydride under solventfree condition with the presence of SSA as the catalyst.…”