Dr. C. Oliver Kappe , Karl-Franzens University, Graz

How do you see the microwave synthesis market going, is it increasing or decreasing?

At the moment, it is definitely increasing as you can see from looking at the activities of the different instrument manufacturers, in the published literature, the patent literature, and attending conferences like this one (Eurocombi-2).

The whole field started in the mid or late '80s when the first papers were published using domestic kitchen microwave ovens. Of course the whole thing was rather irreproducible. Then in the mid 90's the first instrument companies started to put dedicated microwave reactors out for performing chemical synthesis. And within the last one or two years the field has really taken off and virtually all of the top 20 pharma companies have invested into the technology. The market is certainly going up for microwave chemistry!

Who are the leading suppliers?

There are three main suppliers - Personal Chemistry AB from Sweden, CEM Corp. from the United States and Milestone Inc. which is an Italian-based company. They are the three major suppliers at the moment that exist for dedicated instruments.

How are they positioned in terms of value and specification, how do you think they compare against each other?

I believe the single-mode cavities offered by Personal Chemistry and CEM are very good for small scale drug discovery, automation and combichem applications. The instruments offered by Milestone feature larger microwave cavities for larger scale batch type synthesis, also for highly parallelised 96 well plates formats. For even larger scale synthesis, CEM offers a continuous flow reactor that may be useful for the production of kilogram quantities.

You can do process R & D on microwaves?

Absolutely. Although at the moment, I think we are a few years away for microwaves doing reliable routine kilogram scale synthesis, this is certainly where the whole field is heading.

Also, there are new exciting developments with on-line reaction monitoring and working on an extremely small scale (i.e. for proteomics or PCR work).

What about your own work, what are you working on at the moment?

Being an academic group we are still interested in the specific microwave effect, does it really exist or are the observed rate-enhancements just the consequence of the extremely high reaction temperatures. This is just one side of our research, investigating specific microwave effects. The other side is finding new and difficult reactions that are not easy to do conventionally and transforming them into reliable, scalable microwave protocols. We also have a strong interest in interfacing combinatorial applications (solid-phase synthesis, parallel processing, robotics) with microwave applications Additionally, we have just started to work with continuous flow reactors for scale-up purposes and in the proteomics area.

So are you developing the equipment yourself?

No, we are exclusively using commercially available equipment, but we work together with several instrument suppliers and constantly to suggest improvements.

I believe you run a website for this new area?

Indeed, we are also active in educating scientists about the properties of microwaves. After talking to people at this conference it is apparent that many chemists still have very little knowledge about microwaves, and believe it is mostly magic! We are trying to educate people to understand basic principles of microwave chemistry. We are running short courses for the American Chemical Society at their national meetings and also for the European Society for Combinatorial Sciences at the Eurocombi meetings and other related events. Since we have virtually all commercially available microwave reactors in our labs in Graz we are also organizing practical training sessions on microwave synthesis. The next short course is going to be held in our labs on September 22-23, 2003 in Graz, Austria.

We constantly update our website, with the latest information, exciting articles, news, links to instrument vendors, upcoming short courses an education context.

Further Information: http://www.maos.net