CH 3CH 2CO Cl is propanoyl chloride (or propionyl chloride). Acid Halides: The acyl group is named first, followed by the halogen name as a separate word.Į.g. A Greek letter identifies the location of the alkyl oxygen relative to the carboxyl carbonyl group. CH 3(CH 2) 2CO 2 C 2H 5 is ethyl butanoate (or ethyl butyrate).Ĭyclic esters are called lactones. Esters: The alkyl group is named first, followed by a derived name for the acyl group, the oic or ic suffix in the acid name is replaced by ate.Į.g. In the following examples the IUPAC names are color coded, and common names are given in parentheses. These are often used in common names of compounds. Three examples of acyl groups having specific names were noted earlier. Indeed, if hydrogen bonding is not present, the boiling points of comparable sized compounds correlate reasonably well with their dipole moments. The relatively high boiling points of equivalent 3º-amides and nitriles are probably due to the high polarity of these functions. The last nine entries in the above table cannot function as hydrogen bond donors, so hydrogen bonded dimers and aggregates are not possible. Physical Properties of Some Carboxylic Acid Derivatives Similar hydrogen bonding occurs between molecules of 1º and 2º-amides (amides having at least one N–H bond), and the first three compounds in the table serve as hydrogen bonding examples. As noted earlier, the relatively high boiling point of carboxylic acids is due to extensive hydrogen bonded dimerization. Boiling points are given for 760 torr (atmospheric pressure), and those listed as a range are estimated from values obtained at lower pressures. An aldehyde and ketone of equivalent molecular weight are also listed for comparison. The following table lists some representative derivatives and their boiling points. Some examples of these functional derivatives were displayed earlier. Carboxylic acids have a hydroxyl group bonded to an acyl group, and their functional derivatives are prepared by replacement of the hydroxyl group with substituents, such as halo, alkoxyl, amino and acyloxy. If these same functional groups are attached to an acyl group (RCO–) their properties are substantially changed, and they are designated as carboxylic acid derivatives. The important classes of organic compounds known as alcohols, phenols, ethers, amines and halides consist of alkyl and/or aryl groups bonded to hydroxyl, alkoxyl, amino and halo substituents respectively.
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