Substitution Products of the Group

Substitution Products of the Group VIB Metal Carbonyls Gerard R. Dobson, Ingo W. Stolz, and Raymond K. Sheline... 

Nitrofuran antibacterials are synthetic compounds that are substitution products of the 5-nitrofuran nucleus, differing in the substituent at position 2. This substituent may be an azomethine group connected with other ring systems, or an alkyl, acyl, hydroxyalkyl, or carboxyl group, free or esterified. All these antibacterials are susceptible to photolysis, particularly by sunlight, and manipulations must be carried out under subdued light. 

It will be recalled that the primary amines are substitution products of the hydrocarbons in which an (—NH2) group, called the amino group, has been substituted indirectly for a hydrogen of the hydrocarbon. They are prepared by treating an alkyl halide with ammonia. 

Halogen Acids Yield Aromatic Halides.— When a water solution of a diazonium salt is heated with a halogen acid the halogen substitution product of the corresponding hydrocarbon is obtained, the diazo group being replaced by the halogen. 

We come now to the hydroxyl substitution products of the benzene hydrocarbons. These derivatives are of two classes A, phenols in which the hydroxyl group is substituted in the ring part of the compound. alcohols in which the hydroxyl group is substituted in the side chain of benzene homologues. Benzene having no side chain yields only the first class of derivatives. Toluene, however, and all the other homologues of benzene yield both classes as follows ... 

Phenol Aldehydes and Ketones.—The most important substitution products of aromatic aldehydes and ketones are those containing the hydroxyl group. Analogous to the phenol alcohols we have the phenol aldehydes and phenol ketones which are ring hydroxy substitution products of the aromatic aldehydes and ketones. 

The different kinds of substitution products of the aromatic acids which it is possible to obtain are very numerous. Without reference to the particular element or group which is substituted we may have the following t) es. 

When more than one hydroxyl group is substituted in the ring of an aromatic acid there will result poly-phenol acids i.e., poly-hydroxy acids. The poly-hydroxy benzoic acids, which include the most important members, bear the same relation to benzoic acid that the ordinary poly-phenols, e.g., pyrocatechinol, resorcinol, pyrogallol, etc. (p. 617), do to benzene. They may also be considered as carboxyl substitution products of the poly-phenols. 

Fumaric and Maleic Acids, C2H2(COOH)2.—The unsaturated dibasic acids stand in the same relation to the unsaturated hydrocarbons as do the saturated acids to the paraffins. In both cases the acids may be considered as substitution products of the hydrocarbons in which hydrogen atoms are replaced by carboxyl groups. The relation is shown by the formulas,—... 

The halogen substitution-products of the hydrocarbons of the acetylene series resemble those derived from hydrocarbons which contain a double bond. The derivatives of acetylene are very unstable. Chloroacetylene is a gas which decomposes instantaneously, with explosion. The substitution-products which contain the =CH group form precipitates with ammoni-acal solutions of silver and cuprous salts. 

Halogen substitution-products of the unsaturated monobasic acids, and of the unsaturated and saturated polybasic acids are known. They form an interesting group of compounds, but it would lead too far to consider them here. A few will be referred to in the discussion of other compounds. 

The derivatives of acetoacetic esters are mixtures of substitution-products of the two forms of the ester. The relation between the amounts of each form present in any substance, varies with the nature of the groups present in the molecule in some, the form which contains the ketone group largely predominates, while in others, the unsaturated compound is present in the larger quantity. The form which contains the hydroxyl group is designated by the word enol that which contains the carbonyl group is the keto form. 

Diphenyl is converted by active oxidizing agents into benzoic acid, CeHs.COOH. The structure of the substitution-products of the hydrocarbon is established by oxidation. The nitrodi-phenyl which is converted into p-nitrobenzoic acid evidently has the nitro group in position 4. Substitution-products of diphenyl which contain the amino group are used in the manufacture of important dyes. 

The compound formed from the silver salt of benzamide and ethyl iodide at 100° is a substitution-product of the amide in which the alkyl group is joined to nitrogen. Like other amides of this class it yields on hydrolysis an acid and an amine —... 

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