Chemists’ work target compounds

The creation of the target compounds is the next process in a chemical synthesis. In a traditional synthesis, a chemist would assemble the synthesis apparatus, charge a round-bottomed flask with the necessary reagents, adjust the temperature of the reaction then allow it to proceed for an appropriate period of time. When the reaction is complete, the chemist would work up the reaction mixture and purify the crude reaction product if necessary. The procedure followed would be recorded in a laboratory notebook along with any purification strategy. 

In 1967 Charles J. Pedersen, then 2 years away from retirement as a research chemist with Du Pont, published an extensive paper detailing the preparation of 33 cyclic polyethers [1], His thorough investigation of these macrocycles was the culmination of several years work initiated by the accidental preparation of dibenzo[18]crown-6 [2], The compound formed as a result of trace amounts of catechol that had contaminated 2-(hydroxyphenoxy)tetrahydropyran used in the synthesis of the original target compound, bis[2-(hydroxyphenoxy)ethyl]ether. The dibenzocrown ether thus became the first of the crown ethers, as Pedersen called them, to be isolated. 

For synthetic chemists working in the area to develop new agrochemicals and medicines, the most challenging target is probably to identify or to generate the prototype compounds having novel lead structures. Regardless of whether the prototype compounds are from synthetic products or not, however, synthetic chemists are supposed to modify the prototype lead structure not only to optimize activity by systematic replacements of substituents and substructures, but also to explore even... 

We hope that information presented in this chapter will be helpfiil for researchers dealing with the chemistry of fused heterocycles not only to reduce the time, for the search for and development of a synthetic approach to target compounds liom readily available derivatives but also to invent radically new methods of synthesis of fused systems with a known combination of heterocycles. In our opinion, this work can stimulate synthetic organic chemists to design a wide range of new pharmaceutically promising compounds. 

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