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Article / Sep 25, 2023

Hazards of a N-Bromosuccinimide solution in N,N-Dimethylformamide

  • Elsa M. Gonçalves
  • Nuno Lousa
  • Filipe Estanislau
  • Pedro Serra Carvalho
Organic Process Research & Development (2023), 27(11), 1975-1983

Following Hovione Process Safety screening procedures, the preparation of a 22 wt % N- Bromosuccinimide (NBS) solution in N,NDimethylformamide (DMF) was studied by means of R C1 isothermal heat flow calorimetry. The mixture revealed a sudden and rapid decomposition with off-gas release, few minutes after reaching 80°C. This triggered a thorough thermal safety investigation using several well-established DTA techniques. The thermal stability data obtained was used to generate a predictive model for this solution decomposition using Advanced Kinetics and Technol. Software (A KTS). The NBS/DMF solution undergoes hazardous thermal decomposition at low temperature, and the safe working temperature (TMRad 24h) for 22% weight was established as 32°C. It was also found evidence for an autocatalytic mechanism and influence of the N BS concentration and the equipment's materials of construction in the decomposition onset and overall energy output. The work described herein highlights the need of important process safety management considerations when handling the N BS/DMF solution at an industrial scale.

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