Acid chlorides nomenclature

The nomenclature of the imidoyl halides is not clearly established I have therefore attempted to select names which identify the compounds as imidoyl halides, and which furthermore, relate to their chemistry. For example. Chemical Abstracts lists the hydroxamoyl chlorides as oximes of the corresponding carboxylic acid chlorides. Although this name is formally correct, it does not reflect the chemistry of this class of compounds, which is closely related to hydroxamic acids, its hydrolysis products. 

The nomenclature of this class of compounds is not at all clear. For example, the following names can be found in the literature hydroxamic acid chlorides, hydroxamic chlorides, hydroximic chlorides (Beilstein lists them as Hydroximsaure chloride ), and acyl and aroylchloride oximes. The latter names are used by Chemical Abstracts, Although the name benzoyl chloride oxime for benzhydroxamoyl chloride is formally correct, it does not reflect the close relationship between hydroxamoyl chlorides and hydroxamic acids, their hydrolysis products. In order to be consistent with the nomenclature used in the earlier chapters, I prefer the term hydroxamoyl to hydroxamic chloride. The interrelationship of the halides with the corresponding acids is shown below, and R is representative of the alkyl, aryl, acyl, aroyl, and carbalkoxy group. 

The chlorides derived from the reaction of aroyl phenylhydrazines with phosphorus pentachloride are recorded in the literature under a variety of names. While Chemical Abstracts lists these compounds as the phenyl-hydrazones of the corresponding acid chlorides (for example, benzoyl chloride phenylhydrazone for C H5CiCl)=NNHC H5), Beilstein uses the terms a-chlorobenzyliden phenylhydrazine or a-chlorobenzal phenyl-hydrazine for this compound. In view of the relationship of the chlorides I with the corresponding acid hydrazides (II), their hydrolysis products, the names hydrazide chlorides or hydrazidoyl chlorides are more appropriate. In order to preserve conformity of nomenclature, the latter name is used in this book. 

This chapter will revisit the lUPAC nomenclature system for aldehydes, ketones, and carboxylic acids, as well as introduce nomenclature for the four main acid derivatives acid chlorides, anhydrides, esters, and amides. The chapter will show the similarity of a carbonyl and an alkene in that both react with a Br0nsted-Lowry acid or a Lewis acid. The reaction of a carbonyl compound with an acid will generate a resonance stabilized oxocarbenium ion. Ketones and aldehydes react with nucleophiles by what is known as acyl addition to give an alkoxide product, which is converted to an alcohol in a second chemical step. Acid derivatives differ from aldehydes or ketones in that a leaving group is attached to the carbonyl carbon. Acid derivatives react with nucleophiles by what is known as acyl substitution, via a tetrahedral intermediate. 

Each of these acid derivatives has a unique system of nomenclature, but all are fundamentally based on the carboxylic acid precursor (the parent acid). Several examples are shown in Table 16.3. Acid chlorides 56 are named by taking... 

Sulfonyl chloride 178 also has the common name oimesyl chloride. Another very common derivative is 4-methylbenzenesulfonyl chloride (179), also called />am-toluenesulfonyl chloride, which is also called tosyl chloride) (nomenclature for benzene-containing compounds is discussed in Chapter 21). This particular compound is introduced here because it so common and clearly fits into this section. Thionyl bromide (SOBrg) converts sulfonic acids to the corresponding sulfonyl bromide. This reaction is exactly analogous to the reactions with carboxylic acids. 

This chapter concerns the preparation and reactions of acyl chlorides acid anhydrides thioesters esters amides and nitriles These com pounds are generally classified as carboxylic acid derivatives and their nomenclature is based on that of carboxylic acids... 

Berzehus (19) further appHed and amplified the nomenclature introduced by Guyton de Morveau and Lavoisier. It was he who divided the elements into metalloids (nonmetals) and metals according to their electrochemical character, and the compounds of oxygen with positive elements (metals) into suboxides, oxides, and peroxides. His division of the acids according to degree of oxidation has been Httie altered. He introduced the terms anhydride and amphoteric and designated the chlorides in a manner similar to that used for the oxides. 

In Chapter 9 you see the basic structure of each of the carboxylic acids and Ccirboxylic acid derivatives. In this chapter we focus on the carboxylic acids and related compounds, such as esters, acyl chlorides, and acid anhydrides, and we also include some information on amides (see Chapter 13 for an additional examination of cimides). Before you can get into synthesis and reactions, though, you need to understand the structure and nomenclature of these compounds. 

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