15430-48-5Relevant articles and documents
Continuous Flow Process for the Synthesis of Betahistine via Aza-Michael-Type Reaction in Water
Sun, Maolin,Yang, Jingxin,Fu, Youtian,Liang, Chaoming,Li, Hong,Yan, Guoming,Yin, Chao,Yu, Wei,Ma, Yueyue,Cheng, Ruihua,Ye, Jinxing
, p. 1160 - 1166 (2021/05/06)
A continuous flow process for the preparation of betahistine with a 90% isolated yield has been reported. 2-Vinylpyridine and saturated methylamine hydrochloride aqueous solution were used as starting materials to achieve excellent results in the silicon carbide flow reactor, which can tolerate the corrosion of chloride ions at high temperature (170 °C) and pressure (25 bar). In the continuous flow process, the product can be obtained in 2.4 min with excellent conversion (>99%) and product selectivity (94%). The throughput can reach 1.06 kg h-1, and the purity of the final product was greater than 99.9% by distillation, which were in accordance with the needs of production. This new process using environmentally friendly water as the solvent is energy-efficient, time- and cost-economic, and offers a 50% reduction in process mass intensity compared to the batch process.
Convenient Continuous Flow Synthesis of N-Methyl Secondary Amines from Alkyl Mesylates and Epoxides
Lebel, Hélène,Mathieu, Gary,Patel, Heena
, p. 2157 - 2168 (2020/11/23)
The first continuous flow process was developed to synthesize N-methyl secondary amines from alkyl mesylates and epoxides via a nucleophilic substitution using aqueous methylamine. A variety of N-methyl secondary amines were produced in good to excellent yields, including a number of bioactive compounds or their precursors. Up to 10.6 g (88% yield) of an N-methyl secondary amine was produced in 140 min process time. The amination procedure included an in-line workup, and the starting mesylate material was also produced in continuous flow from the corresponding alcohol. Finally, an in-line process combining the mesylate synthesis and nucleophilic substitution was developed.
Aza-Michael-type addition reaction catalysed by a supported ionic liquid phase incorporating an anionic heteropoly acid
Ghasemi, Mohammad Hadi,Kowsari, Elaheh,Shafiee, Abbas
supporting information, p. 1150 - 1153 (2016/03/09)
In this work, we have obtained substituted amines under mild conditions in good yields using the Aza-Michael-type addition of various amines to vinyl compounds catalysed by a supported ionic liquid incorporating an anionic heteropoly acid. Different catalysts, including Lewis acids, Br?nsted acids and heteropoly acids were investigated in which heteropoly acids having dual Br?nsted and Lewis acid characteristics were excellent catalysts. The ionic liquid incorporating a polytungstate anion supported on magnetic diatomaceous earth as a magnetically separable heterogeneous catalyst offered the best results in terms of yield. The solid nanocatalyst was easily removed with a magnet.