Continuous flow microfluidic process for synthesis of 3,4-dinitropyrazole

US11319291B1 · kind B1 · utility

Assignee

• United States of America as represented by the Secretary of the Air Force · US

Inventors

• Thorsten G. Schroer · Palmdale, US
• Gregory E. LeCroy · Lancaster, US
• Mayra P. Rodriguez · Lancaster, US
• Sida Wang · Hercules, US
• Miguel Aguila · Palmdale, US

Key dates

• Filing date: Jun 9, 2020
• Grant date: May 3, 2022
• Expiry date: Jan 23, 2041

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01J2219/00984
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Disclosed herein is a synthetic method, apparatus, and system for the continuous-flow synthesis of 3,4-dinitropyrazole from pyrazole in a microfluidic environment. This synthetic strategy consist of three (3) synthetic steps, including (1) N-nitration of pyrazole, (2) thermal rearrangement into 3-nitropyrazole, and (3) 4-nitration of 3-nitropyrazole. The current technique produces 3,4-dinitropyrazole in yields up to 85% in particular embodiments, in comparison to 40-50% yields demonstrated by the current state of-the-art batch process for large scale synthesis from pyrazole.