Haloalkanes naming

There are two ways of naming alkyl halides. The systematic (IUPAC) nomenclature treats an alkyl halide as an alkane with a halo- substituent Fluorine is fluoro-, chlorine is chloro-, bromine is bromo-, and iodine is iodo-. The result is a systematic haloalkane name, as in 1-chlorobutane or 2-bromopropane. Common or trivial names are constructed by naming the alkyl group and then the halide, as in isopropyl bromide. This is the origin of the term alkyl halide. Common names are useful only for simple alkyl halides, such as the following ... 

Where do we stand now, and where do we go from here With Chapter 8, we have begun to discuss a second important functional class of compounds after the haloalkanes, namely, the alcohols. We used the haloalkanes to introduce two major mechanistic pathways radical... 

Although members of the class are commonly called alkyl halides, they are named systematically as haloalkanes (Section 3.4), treating the halogen as a substituent on a parent alkane chain. There are three steps ... 

The names of organic compounds are based on the names of the parent hydrocarbons alcohols contain —OH groups, carboxylic acids contain —COOH groups, and haloalkanes contain halogen atoms. 

Ring opening of epoxides with nucleophiles other than water (Cl, BrT I, NOz , CN ) can also be catalyzed by halohydrin dehalogenase enzymes (EC 3.8.1.5, also named haloalkane dehalogenase or haloalcohd dehalogenase) (Figure 6.74) [197]. 

Common names for simple haloalkanes are accepted by the IUPAC => alkyl halides (radicofunctional nomenclature). 

An alkyl halide (also known as a haloalkane) is an alkane in which one or more hydrogen atoms have been replaced with halogen atoms, such as F, Cl, Br, or I. The functional group of alkyl halides is R—X, where X represents a halogen atom. Alkyl halides are similar in structure, polarity, and reactivity to alcohols. To name an alkyl halide, first name the parent hydrocarbon. Then use the prefix fluoro-, chloro-, bromo-, or iodo-, with a position number, to indicate the presence of a fluorine atom, chlorine atom, bromine atom, or iodine atom. The following Sample Problem shows how to name an alkyl halide. 

Haloalkanes can be regarded as substituted alkanes in which one or more of the hydrogen atoms is replaced by a halogen atom. They are named in a similar fashion to branched-chain alkanes with the halogen atoms treated like branches. For example, the anaesthetic halothane has the structure shown in the diagram and is called 2-bromo-2-chloro-l,l, 1-trifluoroethane. 

It is interesting to note that boiling points of alcohols and phenols are higher in comparison to other classes of compounds, namely hydrocarbons, ethers, haloalkanes and haloarenes of comparable molecular masses. For example, ethanol and propane have comparable molecular masses but their boiling points differ widely. The boiling point of methojqmiethane is intermediate of the two boiling points. 

According to the lUPAC system, alkyl halides are treated as alkanes with a halogen suhstituent. The halogen prefixes are fluoro-, chloro-, bromo- and iodo-. An alkyl halide is named as a haloalkane with an alkane as the parent structure. 

In this chapter, we consolidate the nomenclature of a number of classes of compounds —an undertaking that may not seem very logical to someone who will soon be troubled enough with the chemistry of these compounds let alone their names. We recommend, however, a thorough study now of alkane and haloalkane nomenclature (Section 3-1) followed by a more cursory examination of the rest of the chapter. Then, as unfamiliar names arise, you can quickly review the basic rules for alkanes and proceed to the new class you have encountered. The idea is to have many of the important rules in one place. Nomenclature rules for other types of compounds are given in Chapter 7. 

When a hydrocarbon is substituted with other than alkyl groups a new problem arises, which can be illustrated by CH3CH2C1. This substance can be called either chloroethane or ethyl chloride, and both names are used in conversation and in print almost interchangeably. In the IUPAC system, halogens, nitro groups, and a few other monovalent groups are considered to be substituent groups on hydrocarbons and are named as haloalkanes, nitro-alkanes, and so on. 

Name the following alkanes and haloalkanes. When two or more substituents are present, list them in alphabetical order. 

Initially, Grignard reagents were considered to be nucleophiles reacting mainly in a polar fashion. However, early in the history of Grignard chemistry the concept originated that the reaction could have a radical character. In 1913 [26] and some years later in 1922 [27] the formation of alkenes and alkanes in the reaction of haloalkanes with Grignard reagents in diethyl ether (Scheme 2) had already been attributed to the intermediacy of what was named, /kr alkyls. 

Haloalkanes are named by adding a prefix to the name of the alkane from which they are derived. 

In the lUPAC system, alkyl halides are named as substituted alkanes. The substituent prefix names for the halogens end with o (i.e., fluoro, chloro, bromo, iodo ). Therefore, alkyl halides are often called haloalkanes. 

RX + 2Na- 2NaX+RR The haloalkane is refluxed with sodium in dry ether. The method is named after the... 

Common names for many simple haloalkanes are still widely used, however. In this common nomenclature system, called functional class nomenclature, haloalkanes are named as alkyl halides. (The following names are also accepted by the lUPAC.)... 

COMPOUNDS CONTAINING a halogen atom covalently bonded to an sp hybridized carbon atom are named haloalkanes or, in the common system of nomenciature, alkyl halldes.Jhe general symbol for an alkyl halide is R—X, where X may be F, Ci, Br, or i ... 

In this chapter, we study two characteristic reactions of haloalkanes nucleophilic substitution and /3-elimination. Haloalkanes are useful molecules because they can be converted to alcohols, ethers, thiols, amines, and alkenes and are thus versatile molecules. Indeed, haloalkanes are often used as starting materials for the synthesis of many useful compounds encountered in medicine, food chemistry, and agriculture (to name a few). 

Common names of haloalkanes consist of the common name of the alkyl group, followed by the name of the halide as a separate word. Hence, the name alkyl halide is a common name for this class of compounds. In the following examples, the lUPAC name of the compound is given first, followed by its common name, in parentheses ... 

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