Esters classification tests

After the unknown is assigned to one of the solubility groups (Fig. 2) on the basis of solubility tests, the possible type should be further narrowed by application of classification tests, e.g., for alcohols, or methyl ketones, or esters. 

Claisen head adapter, 20, 26,134 Claisen-Schmidt reaction, 309-317 classification tests, 640-654. See also qualitative analysis alcohols, 640-642 aldehydes, 642-644 alkanes, 644-645 alkenes, 645 alkyl halides, 645-646 aUcynes, 645 amides, 647-648 amines, 648-649 ammonium salts, 647-648 aromatic hydrocarbons, 649-650 carboxylic acids, 650 cycloalkanes, 644-645 defined, 630 enols, 653-654 esters, 650-651 ethers, 651... 

Nitro-esters. These are usually almost white, or yellow. The nitro-group is most likely to be a nuclear substituent of an aromatic parent add or alcohol (or phenol). Apply classification test for the nitro-group. 

Andno-esters, e.g. methyl anthranilate. Classification tests for both the amino- and ester functions are positive. These compounds are most conveniently characterized through the amino-group. 

In chemistry, these four divisions are perfectly reasonable. For example, if we try to use spectra to classify compounds into ketones and esters, there may be some compounds that are bodi or neither. If, on die odier hand, there are only two possible classifications, for example whether a manufacturing sample is acceptable or not, a conclusion about objects in the bottom left or top right is that the analytical data is insufficiently good to allow us to assign conclusively a sample to a graph. This is a valuable conclusion, for example it is helpful to tell a laboratory that their clinical diagnosis or forensic test is inconclusive and diat if tiiey want better evidence they should perform more experiments or analyses. 

To choose proper test substances, McReynolds studied the behavior of a large number of substances of the following compound classes alcohols, glycols, aldehydes, ketones, esters, acetals, ethers, oxides, hydrocarbons, chloro compounds, difunctional and polyfunctional compounds, and other miscellaneous substances. " For the stationary phase classification, he eventually proposed benzene, n-butanol, 2-pentanone, 1-nitropropane, and pyridine to represent compounds of different chemical interactions. " McReynolds characteristic phase constants for these five compounds describe the selectivity of the phase. 

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