Classic qualitative organic analysis

A successful systematic scheme of qualitative analysis for identifying organic compounds was developed early in the twentieth century. This scheme, together with some more recent modifications, is termed classic qualitative organic analysis, and it is the basis for most textbook discussions on the subject (Ref. 1 at the end of Section 25.5, for example). 

One of the classic methods used in qualitative organic analysis to characterize carbonyl compounds depends on the ready formation of crystalline thiosemicarbazones by the action of a thiosemicarbazide on the carbonyl compounds. Not surprisingly, therefore, several recent papers deal with this particular reaction, reporting on investigations of the reaction as such as well as on new examples of its use in synthesis. Carroll and his coworkers found that the course of the reaction of 2-hydroxy-l,4-naphtho-... 

The classic system of qualitative organic analysis consists of six steps, each of which is discussed in the following subsections. The first four steps, which may be carried out in any order, should be completed before performing the qualitative tests for functional groups. The final step must always be the preparation of one or more solid derivatives. 

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