Amines Notes (organic chemistry) PDF

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Amines Notes...

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Amines An amine can be identified by the presence od an amino group -NH2 (ammonia group minus 1 H) whenrein one H has been replaced by an alkyl group. Amines can b classified into primary (1alkyl group, 2 H’s), secondary (2 alkyl groups, one H), and tertiary (3 alkyl groups, no H’s) amines depending on how many alkyl groups replace H atoms. Nomenclature 1. naming amines can be confusing because there are many accepter variations. See eg. A) 2. amines are named as alkanamines. The -e in the alkane name of the longest chain is changed to -amine 3. the chain is numbered to locate the amine group substituents. 4. in a secondary and tertiary amine, the longest chain is numbered. 5. each alkyl group bonded to the N atom is named N-alkyl group. 6. Multiple amines groups are called diamine, triamine etc. 7. when found in compounds with higher priority functional groups (especially O containing functional groups): name the amine group as a substituent (amino). -NH2 : amino-NHR: N-alkylamino-NR2: N,N-dialkylamino-

ANILINE: a common defining molecule. Properties of Amines: Characteristic Higher boiling points than the P hydrocarbon parent chains. Lower melting and boiling points than alcohols of similar molecular weight

Reason olarity of C-N and N-H bonds cause greater intermolecular forces. OH to form H bonds and larger intermolecular forces than N-H bonds

Typically have “Fishy” odours Commonly found in biological proteins and other molecules.

How amines are prepared: Reaction of alkyl halides with ammonia (weak base)

alkylhalide + ammonia  amine + hydrogen halide  Just like substitution reactions of alkanes with halogens, secondary and tertiary amines can be prod. if the rxn is allowed to continue (more H atoms will be replaced w/ alkyl groups)...