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| Milestone's START system offers professional-quality microwave-accelerated organic synthesis, designed and priced specifically for the academic laboratory. |
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Q: What are the principal advantages of microwave synthesis over traditional heating methods?
A: The most dramatic advantage is the speed with which reactions can be completed. Reactions that take days with conventional methods can be completed in minutes in the microwave. This can fundamentally improve time-sensitive activities such as teaching, method development, drug discovery, etc.
Additional advantages include reduced solvent usage (an important environmental consideration, and a source of substantial cost savings), and significant increase in yields, as well as higher product purity due to decreased formation of by-products.
Q: Can't I just use a kitchen microwave in the lab?
A: While some academic labs have used kitchen microwaves in the past, it is strongly recommended that you avoid this practice. There are serious operator safety risks in using domestic microwaves for chemistry. (In the case of teaching labs, this translates into equally serious liability risks.) The manufacturers specifically state that such machines are not designed for purposes other than food preparation.
The EPA-approved methods concerning microwave-enhanced chemistry do not permit the use of domestic microwaves. There have been fires, explosions, and other accidents. One of the key differences between a laboratory unit and a domestic unit is that the cavity is sealed from the electronic components, and volatile fumes are exhausted safely. Laboratory microwaves have many other safety features as well, including control sensors, solvent-resistant coatings, and explosion-tolerant doors.
From a scientific point of view, it is wise to avoid kitchen microwaves because they have hot and cold spots, rather than a homogeneous microwave field. This can lead to non-reproducible results. Also, temperature and pressure control are not available or are inaccurate, so publication of results obtained with kitchen microwaves has less value.
Q: Will I have to alter my existing chemistry?
A: No. Even if you're using a non-polar (microwave-transparent) solvent, your reaction will work in the microwave. Milestone supplies heating buttons and stir bars made of WeflonTM, a unique, inert, graphite-loaded form of Teflon®. When placed in a reaction vessel, a Weflon stir bar or button is heated by the microwave field and subsequently transfers this heat to the solvent. Each Weflon piece is precisely manufactured to contain the same amount of high-purity microwave absorbing material. This ensures reproducible heating conditions from vessel to vessel and run to run.
Although one would expect a pure kinetic enhancement from the use of Weflon, it has been reported that reactions still undergo the previously mentioned time reduction, and yield and purity improvements compared to conventional synthesis. As yet, the reason for this has not been explained—but at least it works!
If you have a question that has not been answered, feel free to send us an inquiry.
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