Screening of potential complexing agents in methyl formate hydrolysis

• Published in: Journal of molecular liquids Vol. 196; pp. 334 - 339
• Main Authors: Jogunola, Olatunde, Salmi, Tapio, Mikkola, Jyri-Pekka
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2014
• Subjects: Accurate calculations; Amines; Complexation power; Complexing agents; Decomposable ion pair; Equilibrium conversion; Hydrolysis; Imidazoles; Ion pairs; Nucleophilic strength; Organosulfur compounds; Screening; Selection criteria; Sulfur compounds; Screening; Decomposable ion pair; Imidazoles; Complexation power; Complexing agents
• ISSN: 0167-7322; 1873-3166; 1873-3166
• DOI: 10.1016/j.molliq.2014.04.007

More than 70 individual compounds, mainly amines, natural products, organophosphates and sulfur-containing organic compounds, deemed as having potentially suitable complexing strength were screened in order to determine their ability to improve the equilibrium conversion of methyl formate hydrolysis. In fact, alkylphosphates, natural products and organosulfur compounds gave lower methyl formate conversions. After careful screening and investigation of the different classes of amines, aromatic heterocyclic and some tertiary amines were chosen for further investigation. However, it was discovered that imidazoles and substituted piperazines came closest to fulfilling most of the selection criteria as a good complexing agent due to their ability to form a reversible ion pair with the acid product, in addition to their high boiling point, low nucleophilic strength, less bulkiness and thermal stability. A general procedure was proposed for the screening of potential complexing agents. This approach was proven as a rapid one, consumed fewer chemicals and could be used to estimate the complexation power of different candidate compounds in the hydrolysis–complexation process when accurate calculation tools are not available. [Display omitted] •74 compounds were screened to ascertain their ability to increase formic acid yield in methyl formate hydrolysis.•Alkylphosphates, natural products, taurines, 1° and unprotected 2° amines were discarded in the pre-screening stage.•Selection criteria were set for the proper screening based on the results of the pre-screening stage.•Shielded 2° amines tested formed stable adduct with the acid, while some 3° and heterocyclic amines formed reversible ion pair.•Butylimidazole and 1,2,4-trimethylpiperazine fulfilled nearly all the selection criteria.