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Chem 1152: Ch. 16

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Chem 1152: Ch. 16. Amines. Nitrogen. Mostly inert gas (N 2 ) under standard conditions ~78% of atmosphere Found in: Ammonia (NH 3 ) Nitrates (fertilizers) Nitric acid (HNO 3 ) Propellants (N 2 O, nitrous oxide) Explosives (nitroglycerine) Cyanides (CN - ) - PowerPoint PPT Presentation
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  • Chem 1152: Ch. 16Amines

  • NitrogenMostly inert gas (N2) under standard conditions~78% of atmosphereFound in:Ammonia (NH3)Nitrates (fertilizers)Nitric acid (HNO3)Propellants (N2O, nitrous oxide)Explosives (nitroglycerine)Cyanides (CN-)4th most abundant element in human bodyCritical to building blocks of life/CNS functionProteinsDNARNANeurotransmittersAmino acidnitroglycerine

  • AminesOrganic derivatives of ammoniaOne or more H atoms replaced by aromatic or alkyl groupSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011ammoniaPrimary (1)Secondary (2)Tertiary (3):alcohols:::R-OH

  • Naming Amines Common NamesCommon namesFor low MW aminesAlphabetically link names of alkyl or aromatic groups bonded to nitrogen, attach suffix amine.methylamineethylmethylaminetrimethylaminepropylaminemethylphenylamine

  • Naming Amines IUPAC NamesReplace e in alkane with amine.Number position of amino group lowest on parent chain.If substituent on nitrogen, prefixed with N.

  • Naming Amines IUPAC NamesReplace e in alkane with amine.Number position of amino group lowest on parent chain.If substituent on nitrogen, prefixed with N.3-Pentanamine3-Methyl-1-butanamineN-Methyl-2-butanamine2-HexanamineN-Methyl-2-hexanamineN,N-Dimethyl-2-hexanamineN-Ethyl-N-methyl-2-hexanamine2,5-hexanediaminecyclohexylamine

  • Naming Amines Aromaticsaniline3-EthylanilineN-Ethyl-N-methylaniline2-MethylanilineUsually named as substituted anilinesFor groups on N of aniline, identify with N to indicate not attached to ringN-EthylanilineN,N-dimethylanilinediphenylamine2-Ethyl-N-methylanilineN-Ethyl-2-methylaniline3-phenyl-2-heptanamine

  • Physical Properties of Amines1 and 2 amines form H-bonds among themselvesBonds weaker for amines than alcohols (EN of oxygen > nitrogen)BPs of 1 and 2 amines lower than alcohols of comparable MWalcoholamineAmines with fewer than 6 Cs (1, 2 and 3) soluble in water due to H-bondingAmines stink!Low MW amines smell like ammoniaHigher MW amines smell like rotten fishputrescinecadaverine

  • Chemical Properties of AminesBasicity: Amines are weak bases From Brnsted-LowryBase accepts proton and becomes a conjugate acid

  • Chemical Reactions of AminesAmines reversibly react with water, form hydroxide ionsAmines form salts when they react with acids

  • Amine SaltsNaming: Change amine to ammonium and add name of negative ion derived from acidEthyldimethylamine (common)N,N-dimethylethanamine (IUPAC)ethyldimethylammonium bromideAmine salts are white crystalline solids with high MPs.Amine drugs usually given in form of salts to improve their ability to dissolve in body fluidsSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011ethyldimethylammonium

  • Amine SaltsAmine salts are pH dependent, like CAs.amine(high pH)amine salt(low pH)Amine salts may have 4 alkyl/benzene groups quaternary ammonium saltsAcetylcholine is important QA salt involved in transmission of nerve impulses Some QA salts have antiseptic qualities that kill bacteria and fungii.e.g. benzalkonium (Zephiran) chloride used by physicians to scrub before surgery and to sterilize instruments

    Seager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011

  • AmidesAmides are combination of CA and ammonia or amine joined by amide linkage.Ammonia or amineAmide linkageCarboxylic AcidCarboxylic AcidAlcoholEster linkageAmideEsterNot formed by reaction between CA and amine (produces salt)

  • Amines Form AmidesAmides are formed through reaction of primary and secondary amines with acid chlorides and acid anhydrides.Similar to esterification reactions.Seager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011

  • Amide ReactionsNo Rxn

  • Synthesis of NylonSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011CarpetingClothingMedical tubingSuturesParachutes

  • Aspirin SubstitutesSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011Acetylsalicylic acidAspirinPain relieverFever reducerAnti-inflammatoryHarmful side effectsAllergic reactionsGastrointestinal bleedingCan induce Reyes syndrome in children

    AcetaminophenPain relieverFever reducerDoes not irritate intestinal tractNegativesNot an anti-inflammatoryOveruse can lead to liver and kidney damage

  • Amines as NeurotransmittersSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011Neurotransmitters: Molecules that carry chemical messages between neurons in nervous systemreleased into synapse (gap between synaptic terminal of one neuron and Dendrite of another) in response to electrical signalDiffuse across synapse and bind to receptors on dendrites of next neuron

    neuron

  • Amines as NeurotransmittersSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011In CNS (brain and spinal cord), the most important neurotransmitters are amines:AcetylcholineNorepinephrineDopamineSerotoninIn addition to being chemical messengers, some neurotransmitters may also be partly responsible for moods, mental illness

  • Amines and Mental IllnessSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011Neurotransmitters dopamine and norepinephrin both derived from tyrosineTyrosine essential AA obtained from diet (egg whites, turkey, soy)Norepinephrine and epinephrine (adrenaline) act as drugs related to fight or flight responsedirectly increasing heart rate triggers the release of glucose from energy stores increases blood flow to skeletal muscleincreases the brain's oxygen supplyExcess norepinephrine (NE) results in feelings of elationLow NE levels may cause depression

  • Amines and Mental IllnessSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011Derived from the AA tryptophan, another essential AA obtained from dietInfluences sleeping, regulation of body temp., sensory perceptionMay be related to mental illness

  • AmphetaminesSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011Amphetamines structurally and chemically similar to adrenalineRaise glucose level in bloodIncrease pulse rateIncrease blood pressureMay be legally prescribed to elevate mood or reduce fatigueStreet names:Bennies, pep pills, Reds, red devils, speed, dexies, uppers

  • AlkaloidsSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011Weakly basic amines derived from plantsStimulate CNS/Resp. systemsTreatment of malariaCNS Depressants, used as painkillersMorphine derivative

  • Naming AmidesSimple amides named after corresponding carboxylic acids by changing ic or oic of acid to amide.Common names are used more often than IUPAC names.formic acidCommon nameIUPAC namemethanoic acidformamidemethanamideacetic acidCommon nameIUPAC nameethanoic acidacetamideethanamidebenzoic acidCommon nameIUPAC namebenzoic acidbenzamidebenzamide

  • Naming AmidesSimple amides named after corresponding carboxylic acids by changing ic or oic of acid to amide.Common names are used more often than IUPAC names.Use italicized capital N to identify alkyl groups bonded to nitrogen.N-methylformamideCommonIUPACN-methylmethanamideN,N-dimethylacetamideN,N-dimethylethanamideN-ethyl-N-methylbenzamideN-ethyl-N-methylbenzamide

  • Naming AmidesSimple amides named after corresponding carboxylic acids by changing ic or oic of acid to amide.Common names are used more often than IUPAC names.Use italicized capital N to identify alkyl groups bonded to nitrogen.N,N-diethylethanamideN-isobutylbutanamideN-ethyl-N-phenylbenzamide2,N-dimethylbenzamide

  • Physical Properties of AmidesUnsubstituted amides can form complex networks of intermolecular H-bondsIncreases MPs of these substancesIncreasing the number of substituents on amide reduces H-bondingReduces MPs and BPsAmides do form H-bonds with waterIncreases solubilitySeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011

  • Amide HydrolysisMost important rxn is hydrolysisMay involve either acid or baseOne of the products will always be a saltSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011

  • Amide HydrolysisSeager SL, Slabaugh MR, Chemistry for Today: General, Organic and Biochemistry, 7th Edition, 2011

  • Amide HydrolysisacetamideAcetic acidAmmonium chlorideN-methylacetamideAcetic acidmethylammonium chlorideN-methylacetamideSodium acetatemethylamine

  • Amide HydrolysisN-ethylbenzamideBenzoic acidEthylammonium chlorideN-ethylbenzamideSodium benzoateEthylamine

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