Company Filing History:
Years Active: 1976-1982
Title: Dieter Pawellek: Innovator in Chemical Processes
Introduction
Dieter Pawellek is a notable inventor based in Leverkusen, Germany. He has made significant contributions to the field of chemistry, particularly in the development of processes for the reduction of polynitrated compounds. With a total of 2 patents, his work has implications in various chemical applications.
Latest Patents
Pawellek's latest patents include a process for the partial reduction of polynitrated diaryl compounds. This innovative method involves reducing compounds with 1-2 moles of sulfides or sulfide-donating compounds per mole of nitro group, in the presence of ammonia, at temperatures ranging from 30 to 110 degrees Celsius. This process yields nitroamino-diaryl compounds, such as the reduction of 4,4'-dinitro-dibenzyl-2,2'-disulphonic acid to 4-nitro-4'-amino-stilbene-2,2'-disulphonic acid. Another significant patent is for preparing 4-amino-diphenylamine, which is achieved by catalytically hydrogenating 4-nitroso-diphenylamine in a water-immiscible solvent using Raney nickel as a catalyst. This hydrogenation reaction is typically conducted at temperatures between 20 and 150 degrees Celsius and can occur under elevated hydrogen pressure.
Career Highlights
Pawellek is associated with Bayer Aktiengesellschaft, a leading global company in the pharmaceutical and chemical sectors. His work at Bayer has allowed him to focus on innovative chemical processes that enhance product development and efficiency.
Collaborations
Throughout his career, Pawellek has collaborated with esteemed colleagues such as Edmund Bielendorfer and Karlfried Wedemeyer. These collaborations have contributed to the advancement of his research and the successful development of his patented processes.
Conclusion
Dieter Pawellek's contributions to chemical processes through his patents reflect his innovative spirit and dedication to advancing the field. His work continues to influence the industry and showcases the importance of research and development in chemistry.