Combinatorial chemistry and multiple parallel synthesis

Mitscher, L.A. and Dutta, A., Combinatorial chemistry and multiple parallel synthesis, in Burger s Medicinal Chemistry and Drug Discovery, Abraham, D.J., Ed., 6th ed., Vol. 2, Drug Development, Wiley, New York, 2003. 

Mitscher, Lester A., and Apurba Dutta. Combinatorial Chemistry and Multiple Parallel Synthesis, John Wiley fit Sons, Inc. Available online. URL http //media.wiley.eom/product data/excerpt/82/04713702/ 0471370282.pdf. Originally published in Burger s Medicinal Chemistry and Drug Discovery, edited by Donald J. Abraham. Vol. 2, Drug Discovery and Development. Hoboken, N.J. Wiley, 2003. 

The introduction of a new pharmaceutical is a lengthy and expensive undertaking. Methods which promise to shorten the time or the cost are eagerly taken up, and this is clearly the case with combinatorial chemistry and multiple parallel synthesis. 

As noted above, the field of combinatorial chemistry and multiple parallel synthesis started with libraries of peptides. In time, unusual residues crept into the products. While this evolutionis still ongoing, it is now accompanied by a major effort to produce libraries of small, drug-like molecules in library form. Many of the methods used for large molecules carry over but the largely non-iterative nature of small molecule synthesis is a significant complication. 

The demand for substances to be tested increased dramatically, and medicinal chemists began to seek new sources of chemicals and faster ways of synthesizing compounds in-house. Combinatorial chemistry and multiple parallel synthesis became attractive propositions. The term combinatorial chemistry tends to be used as an umbrella term for a number of technologies, including multiple parallel synthesis, but this author feels that the two techniques should be defined separately and distinctly. 

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