Research at Holy Cross Leads to Patented Process that is Environmentally Clean

WORCESTER, Mass. – In a patent published on March 26, (U.S. Patent No. 6,362,375), researchers from the chemistry department at the College of the Holy Cross describe a clean alternative for many applications of the Friedel-Crafts Reaction, used to manufacture important products such as the pharmaceutical ibuprofen.

The Friedel-Crafts Reaction is an important chemical process that has changed little since Victorian times, making it one of the "dirtiest" processes used by today's chemical industry. The two-step process uses large amounts of highly acidic reagents. Large quantities of waste are produced from the first step as acidic vapors, and from the second step as an acidic solution that is difficult to discard.

The new process, created by a Holy Cross chemistry professor with assistance from a student, uses a modern catalyst that is stable to water, making the process highly efficient by allowing the two steps to be combined into just one. This form of reaction is slower, but it eliminates the need to use highly acidic materials and it simultaneously eliminates nearly all waste. Virtually all of the chemicals used in the process can be reused in the next batch, without purification. Products may be frequently isolated in high yield and purity after a very simple isolation.

The principal inventor is Martin A. Walker, a former Holy Cross chemistry professor (now at SUNY Potsdam, NY). He was assisted by Patrick Birmingham, a 1998 graduate of Holy Cross (who is now at Loyola University Medical School in Ill.) as part of the College's undergraduate research program. Dr. Walker is developing specific applications of the process to make ibuprofen and Valium ™ (Roche Laboratories). The work has already attracted interest from both industry and academia, and Walker is hopeful the process will be used widely by the chemical industry.