Selective N-monomethylation of primary anilines with dimethyl carbonate in continuous flow
- Hyowon Seo, Anne-Catherine Bédard, Willie P. Chen, Robert W. Hicklin, Alexander Alabugin, Timothy F. Jamison
- Department of Chemistry, Massachusetts Institute of Technology, 77 Massachusetts Ave., Cambridge, MA 02139, USARead the publication that featured this abstract
Selective N-monomethylation of anilines has been achieved under continuous flow conditions using dimethyl carbonate as a green methylating agent in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene. Our methodology takes advantage of the expanded process windows available in the continuous flow regime to safely induce monomethylation in superheated solvents at high pressure. We propose selective N-monomethylation is achieved via an in situ protection-deprotection pathway, which is supported by the observed reactivities of several putative reaction intermediates. The robust and scalable method was applicable to a broad range of primary aniline substrates including ortho-, meta-, and para-substituted anilines, as well as electron-rich and electron-deficient anilines. The synthetic precursor of diazepam, 5-chloro-2-(methylamino)benzophenone, was selectively synthesized under our optimized conditions.
The Vapourtec R-Series is, quite simply, unrivalled for flow chemistry
- Flexible :
- Precise :
The R-Series is undoubtedly the most versatile, modular flow chemistry system available today.
The Vapourtec E-Series is the perfect introductory system for flow chemistry
- Robust :
- Easy to use :
The E-Series is a robust and affordable, entry level flow chemistry system designed for reliability and ease of use.