Thomas M. Bass, Daniel Zell*, Sean M. Kelly*, Thomas C. Malig, José G. Napolitano, Lauren E. Sirois, Chong Han and Francis Gosselin,
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引用次数: 0
Abstract
Herein, we describe the development of two continuous manufacturing processes for the synthesis of 6-chloro-1H-pyrazolo[3,4-b]pyrazine, which is a key intermediate en route to the SHP2 inhibitor GDC-1971 (migoprotafib). The reaction sequence starts with a plug-flow metalation/formylation of readily available 2,6-dichloropyrazine using i-Pr2NMgCl·LiCl (MgDA) as the base, whereupon the resulting unstable heteroaryl aldehyde intermediate is isolated as its easier-to-handle and bench-stable bisulfite adduct. The ensuing cyclization step to the pyrazolopyrazine product necessitates the use of excess amounts of hydrazine reagent, and involves the accumulation of highly energetic, nitrogen-rich intermediates. A continuous stirred-tank reactor (CSTR) process was engineered to address the associated safety concerns while accommodating for the heterogeneity of the reaction mixture. These two safe and robust continuous processes have been demonstrated on multikilogram scale, and serve as enabling contributions toward large-scale manufacturing of GDC-1971.
期刊介绍:
The journal Organic Process Research & Development serves as a communication tool between industrial chemists and chemists working in universities and research institutes. As such, it reports original work from the broad field of industrial process chemistry but also presents academic results that are relevant, or potentially relevant, to industrial applications. Process chemistry is the science that enables the safe, environmentally benign and ultimately economical manufacturing of organic compounds that are required in larger amounts to help address the needs of society. Consequently, the Journal encompasses every aspect of organic chemistry, including all aspects of catalysis, synthetic methodology development and synthetic strategy exploration, but also includes aspects from analytical and solid-state chemistry and chemical engineering, such as work-up tools,process safety, or flow-chemistry. The goal of development and optimization of chemical reactions and processes is their transfer to a larger scale; original work describing such studies and the actual implementation on scale is highly relevant to the journal. However, studies on new developments from either industry, research institutes or academia that have not yet been demonstrated on scale, but where an industrial utility can be expected and where the study has addressed important prerequisites for a scale-up and has given confidence into the reliability and practicality of the chemistry, also serve the mission of OPR&D as a communication tool between the different contributors to the field.