Hang Zhao, Xiao Xiao, Runqi Hao, Dan Chen, Jiawei Ke, Minjie Liu, Li Wan, Fener Chen
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引用次数: 0
Abstract
1-Chloro-3-methyl-2-butene is an important synthetic precursor or alkylating agent in the preparation of various bioactive chemicals and essential nutrients for human beings. A flow surface-mediated HCl in situ generation and subsequent hydrochlorination of isoprene were realized in the PTFE tubing reactor and the packed-bed reactor separately. Up to 86% isolated yield of 1-chloro-3-methyl-2-butene was achieved in the packed-bed reactor by performing the flow hydrochlorination at -15 °C within a 15 min residence time in the presence of 0.5 equiv. SOCl2. The in-line recycling and regenerating of solid proton donor Al2O3 were accomplished via simple washing with DCM and MeOH in sequence, the activity of Al2O3 filled in the packed-bed reactor maintain consistent on the isolated yield of 1-chloro-3-methyl-2-butene after ten times consecutive reutilization. The flow platform consisting of two parallel packed-bed reactors were assembled for the continuous synthesis of desired 1-chloro-3-methyl-2-butene without interruption through delicate coordinating opening direction of a series of three-way valves. Long-term stability and reliability were demonstrated by continuous running the designed cyclic rotation system for 10 h, the targeted hydrochlorination product was furnished in 91–93% yield.
Graphical abstract
Continuous-flow synthesis of prenyl chloride was enabled by cross-sequential utilization strategy using two parallel packed-bed reactors and precise alternating a series of three-way valves opening direction.
期刊介绍:
The main focus of the journal is flow chemistry in inorganic, organic, analytical and process chemistry in the academic research as well as in applied research and development in the pharmaceutical, agrochemical, fine-chemical, petro- chemical, fragrance industry.