We present an in-depth study of the acetylation of benzyl alcohol in the presence of N, N-diisopropylethylamine (DIPEA) by nuclear magnetic resonance (NMR) monitoring of the reaction from 1.5 s to several minutes. We have adapted the NMR setup to be compatible to microreactor technology, scaling down the typical sample volume of commercial NMR probes (500 μL) to a microfluidic stripline setup with 150 nL detection volume. Inline spectra are obtained to monitor the kinetics and unravel the reaction mechanism of this industrially relevant reaction. The experiments are combined with conventional 2D NMR measurements to identify the reaction products. In addition, we replace DIPEA with triethylamine and pyridine to validate the reaction mechanism for different amine catalysts. In all three acetylation reactions, we find that the acetyl ammonium ion is a key intermediate. The formation of ketene is observed during the first minutes of the reaction when tertiary amines were present. The pyridine-catalyzed reaction proceeds via a different mechanism.
Download full-text PDF |
Source |
|---|---|
| http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6449804 | PMC |
| http://dx.doi.org/10.1021/jacs.9b00039 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Simultaneous separation and detection of common chiral and achiral metabolites in the urine of human exposed to benzene series by LC-MS/MS.
J Chromatogr B Analyt Technol Biomed Life Sci
January 2025
School of Ecology and Environment, Yuzhang Normal University, No.1999, Meiling Ave., Honggutan Dist., Nanchang 330103, Jiangxi, China.
Benzene, toluene, and xylene (BTX) are priority pollutants known for their hematotoxicity and carcinogenic properties. Benzene is further metabolized to phenyl mercapturic acid (PMA), toluene and xylene also generate benzyl mercapturic acid (BMA) in human urine. To confirm whether the exposure to benzene series comes from the workplace or from the external environment such as smoking is a very meaningful work, so accurate measurement of their biomarkers in biological samples is crucial.
View Article and Find Full Text PDFUtilizing ESI-MS/MS and ion mobility spectrometry for structural characterization and isomer differentiation of 1, 2-unsaturated (1-4) linked disaccharide derivatives and their 2-C-functionalized analogues.
Rapid Commun Mass Spectrom
December 2024
Institute of Chemistry, University of Potsdam, Potsdam, Germany.
Rationale: The 1, 2-unsaturated derivatives of (1-4) linked disaccharides serve as versatile building blocks for synthesizing biologically active compounds. Distinguishing between four pairs of stereoisomers in mixtures presents a challenging task. In this study, disaccharide derivatives are analyzed as alkali metal adducts using electrospray ionization tandem mass spectrometry (ESI-MS/MS), both as individual compounds and in mixtures by ion mobility mass spectrometry (IMS).
View Article and Find Full Text PDFMetabolic engineering of Escherichia coli for high-level production of benzyl acetate from glucose.
Microb Cell Fact
September 2024
Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
Background: Benzyl acetate is an aromatic ester with a jasmine scent. It was discovered in plants and has broad applications in food, cosmetic, and pharmaceutical industries. Its current production predominantly relies on chemical synthesis.
View Article and Find Full Text PDFChemoselective Hydrogenation of α,β-Unsaturated Anilides Catalyzed by Palladium-Hydrosilane System.
Chem Pharm Bull (Tokyo)
August 2024
Graduate School of Biomedical and Health Sciences, Hiroshima University.
We report chemoselective hydrogenation of α,β-unsaturated anilides catalyzed by the palladium-polymethylhydrosiloxane (hydrosilane) system. Under this condition, C-C double bonds are selectively reduced while other reducible groups such as acetyl groups, nitro groups, nitriles, benzyl ethers, and halogens are largely tolerated. This chemoselective hydrogenation is promising for the development of efficient synthetic routes for multi-functional compounds.
View Article and Find Full Text PDFDevelopment of an integrated strategy for comprehensive characterization of Sinomenii Caulis extract and metabolites in rats based on UPLC/Q-TOF-MS.
J Pharm Biomed Anal
October 2024
State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China. Electronic address:
Article Synopsis
- Sinomenii Caulis (SC) is a traditional Chinese medicine primarily studied for its therapeutic effects on rheumatoid arthritis, but research has mostly centered on sinomenine rather than exploring other alkaloids.
- This study utilized advanced techniques (UPLC/Q-TOF-MS) to analyze SC's chemical profile and its effects on rats, identifying 114 alkaloid compounds and 324 metabolites in biological samples like plasma and urine.
- The findings highlight various metabolization processes and offer a comprehensive strategy for better understanding the compound diversity in SC, potentially aiding in the discovery of new treatments for rheumatoid arthritis.
Want AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!