The classes of compounds, which may be considered as derivatives of ammonia, in which the H atoms are replaced with alkyl or aryl groups. Aliphatic Amines-those in which the N is bonded only to alkyl groups. Classification of Amines. In addition, it is common practice to classify amines according to how many alkyl groups are attached to the N atom. Classifying functional groups in this fashion is especially helpful when studying the variety of reactions of a particular group.
When the N is attached to one alkyl group, it is primary 1 o ; two alkyl groups, secondary 2 o ; and three alkyl groups, tertiary 3 o. Some examples are shown in the table:. Common Names. The common name is formatted by identifying the alkyl group attached to the N atom and adding, the term amine.
Methanamine is also known as methylamine ; ethanamine is ethylamineetc. Aromatic Amines-those in which the N is bonded to at least one aromatic aryl group. The simplest member of this family is aminobenzene, which is more commonly known as aniline.
Other alkyl groups may also be attached to the N atom, and these are indicated by naming the alkyl group and placing a N- as a prefix. This notation N- indicates that the groups are attached to the nitrogen atom, as opposed to another site in the structure.
See section on Aromatic Nomenclature. Unsaturated Amines. If there is stereochemistry about the alkene, it too is incorporated. Some simple examples are shown in the Table below:. JA Colapret. N -Methylaniline. N,N -Dimethylaniline. N - Methylaminobenzene.For details on it including licensingclick here. This book is licensed under a Creative Commons by-nc-sa 3.
See the license for more details, but that basically means you can share this book as long as you credit the author but see belowdon't make money from it, and do make it available to everyone else under the same terms. This content was accessible as of December 29,and it was downloaded then by Andy Schmitz in an effort to preserve the availability of this book. Normally, the author and publisher would be credited here.
However, the publisher has asked for the customary Creative Commons attribution to the original publisher, authors, title, and book URI to be removed. Additionally, per the publisher's request, their name has been removed in some passages. More information is available on this project's attribution page.
For more information on the source of this book, or why it is available for free, please see the project's home page. You can browse or download additional books there. To download a. The amide functional group has an nitrogen atom attached to a carbonyl carbon atom.
If the two remaining bonds on the nitrogen atom are attached to hydrogen atoms, the compound is a simple amide. If one or both of the two remaining bonds on the atom are attached to alkyl or aryl groups, the compound is a substituted amide.
The carbonyl carbon-to-nitrogen bond is called an amide linkage.
This bond is quite stable and is found in the repeating units of protein molecules, where it is called a peptide linkage. Simple amides are named as derivatives of carboxylic acids. Help Creative Commons. Creative Commons supports free culture from music to education.
Their licenses helped make this book available to you. Help a Public School. Previous Section. Table of Contents. Next Section.Amides are pervasive in nature and technology. Proteins and important plastics like NylonsAramidTwaronand Kevlar are polymers whose units are connected by amide groups polyamides ; these linkages are easily formed, confer structural rigidity, and resist hydrolysis. In biochemistrythe amide group is called a peptide bond when it is part of the main chain of a protein, and isopeptide bond when it occurs in a side chain, such as in the amino acids asparagine and glutamine.
Amides include many other important biological compounds, as well as many drugs like paracetamolpenicillin and LSD. In the usual nomenclature, one adds the term "amide" to the stem of the parent acid's name.
IUPAC recommends ethanamidebut this and related formal names are rarely encountered. When the amide is derived from a primary or secondary amine, the substituents on nitrogen are indicated first in the name.
Usually even this name is simplified to dimethylacetamide. Cyclic amides are called lactams ; they are necessarily secondary or tertiary amides. The lone pair of electrons on the nitrogen atom is delocalized into the carbonyl group, thus forming a partial double bond between nitrogen and carbon.
In fact the O, C and N atoms have molecular orbitals occupied by delocalized electronsforming a conjugated system. Consequently, the three bonds of the nitrogen in amides is not pyramidal as in the amines but planar. The structure of an amide can be described also as a resonance between two alternative structures:. There is also a hydrogen bond present between the active groups hydrogen and nitrogen atoms. Compared to aminesamides are very weak bases. While the conjugate acid of an amine has a p K a of about 9.
Therefore, amides don't have as clearly noticeable acid—base properties in water. This relative lack of basicity is explained by the withdrawing of electrons from the amine by the carbonyl. The proton of a primary or secondary amide does not dissociate readily under normal conditions; its p K a is usually well above It is not only because of the positive charge on the nitrogen, but also because of the negative charge on the oxygen gained through resonance.
In primary and secondary amides, the presence of N—H dipoles allows amides to function as H-bond donors as well. Thus amides can participate in hydrogen bonding with water and other protic solvents; the oxygen atom can accept hydrogen bonds from water and the N—H hydrogen atoms can donate H-bonds. As a result of interactions such as these, the water solubility of amides is greater than that of corresponding hydrocarbons.
These hydrogen bonds are also have an important role in the secondary structure of proteins. The solubilities of amides and esters are roughly comparable.
Typically amides are less soluble than comparable amines and carboxylic acids since these compounds can both donate and accept hydrogen bonds. Tertiary amides, with the important exception of NN -dimethylformamideexhibit low solubility in water.Primary amides are named by changing the name of the acid by dropping the -oic acid or -ic acid endings and adding -amide. The carbonyl carbon is given the 1 location number. It is not necessary to include the location number in the name because it is assumed that the functional group will be on the end of the parent chain.
Secondary amides are named by using an upper case N to designate that the alkyl group is on the nitrogen atom. Alkyl groups attached to the nitrogen are named as substituents.
The letter N is used to indicate they are attached to the nitrogen. Try to draw a structure for the following compound: N,N-dimethylformamide. Steven Farmer Sonoma State University. Richard Banks Boise State University. Primary amides Primary amides are named by changing the name of the acid by dropping the -oic acid or -ic acid endings and adding -amide.
Secondary Amides Secondary amides are named by using an upper case N to designate that the alkyl group is on the nitrogen atom. N-methylpropanamide Exercise Try to draw a structure for the following compound: N,N-dimethylformamide.
Tertiary Amides Tertiary amides are named in the same way as secondary amides, but with two N's Exercise Try to draw a structure for N,N-dimethylformamide. Contributors Prof.Primary amides are organic chemical compounds that include the functional group :.
That is, primary amides are a class or category of organic chemical compounds that include a part consisting of a carbon atom connected to both :. These molecules can vary in size up to very long molecules most of which consist of carbon atoms attached to each other and also to hydrogen atoms. Above Top : Simple examples of types of amides Lower : More general representations.
In general, amides are organic chemicals whose molecules include a carbon atom C attached to both an oxygen atom O and a nitrogen atom N.
In the cases of primary amidesthat N is also attached to two hydrogen H atoms, which together are written NH 2. There are also more complicated amides called secondary amides and tertiary amides. In the case of secondary amides one of the hydrogen atoms attached to the nitrogen is replaced by another group or carbon chain e.
Many introductory texts only describe primary amides which are described as simply including the group -CONH 2. As shown, the difference between primary, secondary and tertiary amides is the number of C atoms attached to the N. In all cases, one of the C attached to the N is also attached to an O. An alternative group-name for amides is carboxamidesi.
Amides are named according to the same system as other organic compounds, with the suffix -amide used to designate the presence in the molecule of an amide group. The first step is to consider the number of carbon atoms forming a chain. If they are in an unbranched configuration then the number of carbon atoms is indicated according to the same system as used for linear alkanes and as shown in the table below. If the carbon atoms do not form a single chain but include branches, the longest chain of carbon atoms within the molecule determines the base of the name of the compound onto which is added information about the branches incl.
The first 10 members of the homologous series of linear primary amides, i. Why stop at ten carbon atoms in the chain? It doesn't. There are more similar linear amides. We stopped here due to page width.
They have not all been verified and may include common non-scientific names and trade names specific to particular suppliers. The purpose of these lists is to give a general indication of the range of names by which these amides are, or have been, known. Note : This is one of many pages about types of organic compounds in our Organic Chemistry Section.
Similar and related pages describe hydrocarbonsalkaneshaloalkanesalkenes, alkynescycloalkanesaromatic hydrocarbons arenesalcoholsestersethersaldehydesketonescarboxylic acidsacid chloridesacid anhydridesazo dyes, aminesamidesnitrilesamino acids chemistrypeptides, proteins chemistrypolypeptides and others. If you need further information ask your chemistry tutor.
According to the International Union of Pure and Applied Chemistry IUPAC recommendations for nomenclature of organic chemistry, compounds that include the -amide functional group may be called amidessee more about naming amides.Amine Synthesis Reactions
How to get along when staying at home - 31 Mar ' Kale is in season in February - 7 Feb ' Free to access online data about latest clinical research on novel coronavirus nCoV - 29 Jan 'Amines are molecules that contain carbon-nitrogen bonds. The nitrogen atom in an amine has a lone pair of electrons and three bonds to other atoms, either carbon or hydrogen. Various nomenclatures are used to derive names for amines, but all involve the class-identifying suffix —ine as illustrated here for a few simple examples:.
In some amines, the nitrogen atom replaces a carbon atom in an aromatic hydrocarbon. A heterocyclic compound contains atoms of two or more different elements in its ring structure. The illustration shows one of the resonance structures of pyridine. The genetic material for all living things is a polymer of four different molecules, which are themselves a combination of three subunits.
The genetic information, the code for developing an organism, is contained in the specific sequence of the four molecules, similar to the way the letters of the alphabet can be sequenced to form words that convey information. The information in a DNA sequence is used to form two other types of polymers, one of which are proteins.
The proteins interact to form a specific type of organism with individual characteristics. A genetic molecule is called DNA, which stands for deoxyribonucleic acid.
The four molecules that make up DNA are called nucleotides. Each nucleotide consists of a single- or double-ringed molecule containing nitrogen, carbon, oxygen, and hydrogen called a nitrogenous base.
Each base is bonded to a five-carbon sugar called deoxyribose. The nitrogenous bases of each nucleotide stick out from this sugar-phosphate backbone. DNA is actually formed from two such polymers coiled around each other and held together by hydrogen bonds between the nitrogenous bases. Thus, the two backbones are on the outside of the coiled pair of strands, and the bases are on the inside.
It probably makes sense that the sequence of nucleotides in the DNA of a cat differs from those of a dog. But it is also true that the sequences of the DNA in the cells of two individual pugs differ.
Likewise, the sequences of DNA in you and a sibling differ unless your sibling is an identical twinas do those between you and an unrelated individual. However, the DNA sequences of two related individuals are more similar than the sequences of two unrelated individuals, and these similarities in sequence can be observed in various ways.
This is the principle behind DNA fingerprinting, which is a method used to determine whether two DNA samples came from related or the same individuals or unrelated individuals. DNA is an organic molecule and the genetic material for all living organisms.
Each nucleotide consists of a nitrogenous base a double-ring molecule, in this casea five-carbon sugar deoxyriboseand a phosphate group. Using similarities in sequences, technicians can determine whether a man is the father of a child the identity of the mother is rarely in doubt, except in the case of an adopted child and a potential birth mother. Likewise, forensic geneticists can determine whether a crime scene sample of human tissue, such as blood or skin cells, contains DNA that matches exactly the DNA of a suspect.
Nomenclature of Organic Compounds/Amides
Amine functional groups are found in a wide variety of compounds, including natural and synthetic dyes, polymers, vitamins, and medications such as penicillin and codeine. They are also found in many molecules essential to life, such as amino acids, hormones, neurotransmitters, and DNA.
Since ancient times, plants have been used for medicinal purposes. One class of substances, called alkaloidsfound in many of these plants has been isolated and found to contain cyclic molecules with an amine functional group.This page explains what amides are and looks at their simple physical properties such as solubility and melting points. Amides are derived from carboxylic acids. Notice that in each case, the name is derived from the acid by replacing the "oic acid" ending by "amide".
If the chain was branched, the carbon in the -CONH 2 group counts as the number 1 carbon atom. For example:. A deliquescent substance is one which picks up water from the atmosphere and dissolves in it. Ethanamide crystals nearly always look wet. The melting points of the amides are high for the size of the molecules because they can form hydrogen bonds. The hydrogen atoms in the -NH 2 group are sufficiently positive to form a hydrogen bond with a lone pair on the oxygen atom of another molecule.
As you can see, there is the potential for lots of hydrogen bonds to be formed. Each molecule has two slightly positive hydrogen atoms and two lone pairs on the oxygen atom. These hydrogen bonds need a reasonable amount of energy to break, and so the melting points of the amides are quite high.
The small amides are soluble in water because they have the ability to hydrogen bond with the water molecules.
It needs energy to break the hydrogen bonds between amide molecules and between water molecules before they can mix - but enough energy is released again when the new hydrogen bonds are set up to allow this to happen. If this is the first set of questions you have done, please read the introductory page before you start.
What are amides? Use the BACK button on your browser to return to this page. Solubility in water The small amides are soluble in water because they have the ability to hydrogen bond with the water molecules. Questions to test your understanding If this is the first set of questions you have done, please read the introductory page before you start.