hl organic chemistry topic 20 more functional groups more functional groups amines amines nh 2 nh 2...

HL organic chemistry topic HL organic chemistry topic 2020

More functional groupsMore functional groups AminesAmines NHNH22

Draw 1-aminopropane (propanamine) Draw 1-aminopropane (propanamine) and give condensed formulaand give condensed formula

Methylamine (old) aminomethane Methylamine (old) aminomethane IUPACIUPAC

1,6-diaminohexane1,6-diaminohexane

1-butylamine, 1-butanamine, 1-butylamine, 1-butanamine, 1-aminobutane (all the same) 1-aminobutane (all the same)

Secondary aminesSecondary amines

N-methylpropanamine (name the N-methylpropanamine (name the longest chain)longest chain)

Tertiary aminesTertiary amines

CHCH33CHCH22N(CHN(CH33))22 name and draw name and draw N,N-dimethylpropanamineN,N-dimethylpropanamine

EstersEsters

Yeah, already doneYeah, already done

AmidesAmides

R-CO-NHR-CO-NH22

Name the longest carbon chain Name the longest carbon chain followed by amide (amides on the followed by amide (amides on the end)end)

propanamidepropanamide

2-methylpropanamide2-methylpropanamide

Secondary amidesSecondary amides

N-methylproanamideN-methylproanamide

N,N-dimethylpropanamideN,N-dimethylpropanamide

NitrilesNitriles

R-CNR-CN Used to be cyanides CUsed to be cyanides C22HH55CN ethyl CN ethyl

cyanidecyanide Now propanenitrileNow propanenitrile Draw itDraw it

Draw ethanenitrileDraw ethanenitrile

Pentanenitrile?Pentanenitrile?

Do question 1Do question 1

Nucleophilic substitution Nucleophilic substitution reactionsreactions

-ions or molecules with a nonbonding -ions or molecules with a nonbonding pair of electronspair of electrons

Act as Lewis basesAct as Lewis bases Use curly arrows to show movement Use curly arrows to show movement HH22O, OHO, OH--, CN, CN--, NH, NH33

SSNN2 mechanism2 mechanism

Ammonia and bromoethane forms Ammonia and bromoethane forms ethylamine and hydrogen bromideethylamine and hydrogen bromide

Need conc. NHNeed conc. NH33 and sealed tube for and sealed tube for pressurepressure

forms N-ethylethanamine then N,N-forms N-ethylethanamine then N,N-diethylethanaminediethylethanamine

Eventually tetraethylammonium Eventually tetraethylammonium bromidebromide

Make propan-2-amineMake propan-2-amine

Needed for halogenoalkane Needed for halogenoalkane reactionsreactions

Show bromoethane with potassium Show bromoethane with potassium cyanide(in ethanol and reflux) to cyanide(in ethanol and reflux) to form propanenitrileform propanenitrile

Show the SShow the SNN2 mechanism2 mechanism

Now reduce it to Now reduce it to propanaminepropanamine

Factors affecting the rate of Factors affecting the rate of nucleophilic reactionsnucleophilic reactions

electronegative can easily donate e- electronegative can easily donate e- pairpair

CNCN-- >OH>OH-- >NH >NH33 > H > H22OO Strength of carbon to halogen bond Strength of carbon to halogen bond

remember I >Br to Fremember I >Br to F

Type of mechanism SType of mechanism SNN1(tertiary) 1(tertiary) > > secondary (mixture) > Ssecondary (mixture) > SNN2 (primary)2 (primary)

Do question 2-5Do question 2-5 Lab activityLab activity Do questions 17-19 page 399 for HWDo questions 17-19 page 399 for HW

Elimination reactionsElimination reactions

Halogenoalkanes with hot NaOH in Halogenoalkanes with hot NaOH in alcohol to alkenealcohol to alkene

With water and BrWith water and Br- - also formedalso formed CC22HH55Br to CBr to C22HH44

OHOH- - in hot alcohol, refluxin hot alcohol, reflux

E2 (elimination bimolecular)mechanism to E2 (elimination bimolecular)mechanism to form alkeneform alkene

See pages 400 and 401See pages 400 and 401

Do questions 20-21 page 401 for HWDo questions 20-21 page 401 for HW

Condensation reactionsCondensation reactions

Acids and alcohols with HAcids and alcohols with H22SOSO44 as as catalystcatalyst

HH22O byproduct (makes a longer O byproduct (makes a longer chain)chain)

Pineapple is ethyl butanoatePineapple is ethyl butanoate

Esters have no H bonding, are more Esters have no H bonding, are more volatile, less soluble in watervolatile, less soluble in water

Naturally occurring fats and oilsNaturally occurring fats and oils

Acids with primary amines form Acids with primary amines form secondary amidessecondary amides

Ethanoic acid and metanamineEthanoic acid and metanamine

Secondary amines and acids form a Secondary amines and acids form a peptide bond (tertiary amide)peptide bond (tertiary amide)

Amino acids form peptide bondsAmino acids form peptide bonds

Alanine and glycine can form 2 Alanine and glycine can form 2 dipeptidesdipeptides

Many amino acids form proteinsMany amino acids form proteins

Do question 6-7Do question 6-7 AnimationAnimation

Condensation Condensation polymerizationpolymerization

To make polypeptides or proteinsTo make polypeptides or proteins Hexane-1,6-dioic acid with 1,6-Hexane-1,6-dioic acid with 1,6-

diaminohexane to form polyamide diaminohexane to form polyamide nylonnylon

Polyesters like dacronPolyesters like dacron Benzene-1,4-dicarboxylic acid and ethane-1,2-diol Benzene-1,4-dicarboxylic acid and ethane-1,2-diol

draw this monomer (polyester) draw this monomer (polyester) PET is polyethene-1,4-benzoate used for plastic PET is polyethene-1,4-benzoate used for plastic

bottlesbottles

Do question 8Do question 8 Do questions 22-24 page 406 for HWDo questions 22-24 page 406 for HW

Reaction pathwaysReaction pathways

Add nitrile, amine and amide to your Add nitrile, amine and amide to your algorithmsalgorithms

How can bromoethane be How can bromoethane be converted to propanamine?converted to propanamine?

Convert ethanol to N-Convert ethanol to N-methylethanamide using methylethanamide using

another organic compoundanother organic compound

Do questions 25-27 page 407 for HWDo questions 25-27 page 407 for HW Lab activityLab activity

StereoisomerismStereoisomerism

Same molecular and structural Same molecular and structural formula but atoms arranged formula but atoms arranged differently in spacedifferently in space

geometricalgeometrical

Multiple bonds cannot be rotatedMultiple bonds cannot be rotated Cis transCis trans But-2-eneBut-2-ene Build thisBuild this

Draw and name the geometric Draw and name the geometric isomers of but-2- enedioic acidisomers of but-2- enedioic acid

Similar properties but not the sameSimilar properties but not the same Depends on the functional group Depends on the functional group Polarity, shape and symmetry of the Polarity, shape and symmetry of the

moleculesmolecules

Cis and trans 1,2-Cis and trans 1,2-dichlorethenedichlorethene

Which has the higher boiling point, Which has the higher boiling point, melting pointmelting point

Can occur in cyclic compoundsCan occur in cyclic compounds 1,2-dimethylcyclopropane cis and 1,2-dimethylcyclopropane cis and

transtrans

5 isomers of dichlorocyclobutane5 isomers of dichlorocyclobutane 2 are cis 2 are trans2 are cis 2 are trans

Cis and trans-but-2-ene-1,4-dioic acidCis and trans-but-2-ene-1,4-dioic acid trans strong H bonding mp 286 trans strong H bonding mp 286 ooC C

and cannot form cyclic anhydrideand cannot form cyclic anhydride

H bonding in moleculeH bonding in molecule cis mp 131 cis mp 131 ooC with heat trans can C with heat trans can

form cis-but-2-ene-1,4-dioic form cis-but-2-ene-1,4-dioic anhydrideanhydride

lab activitylab activity

Optical isomerismOptical isomerism

Asymmetric carbon atom (chiral) 4 Asymmetric carbon atom (chiral) 4 different groupsdifferent groups

Make a model of a chiral carbon and Make a model of a chiral carbon and its stereoisomerits stereoisomer

Mirror images = enantiomersMirror images = enantiomers Do question 9Do question 9

Drawings of enantiomersDrawings of enantiomers Use an asterisk to designate the Use an asterisk to designate the

chiral carbonchiral carbon Butan-2-olButan-2-ol

2-bromobutane2-bromobutane

Draw the enantiomers of 2-Draw the enantiomers of 2-hydroxypropanoic acid (lactic hydroxypropanoic acid (lactic acid) Mark the chiral carbon acid) Mark the chiral carbon atom and show the plane of atom and show the plane of

the mirrorthe mirror

Demonstration of plane polarized lightDemonstration of plane polarized light Dextrorotatory d- rotated clockwise Dextrorotatory d- rotated clockwise

with a polarizor to get maximum with a polarizor to get maximum intensityintensity

Lavorotatory l- counter clockwiseLavorotatory l- counter clockwise Mixture of both is racemicMixture of both is racemic animationsanimations

Usually same chemical and physical Usually same chemical and physical propertiesproperties

Exception is when they interact with Exception is when they interact with other optically active substancesother optically active substances

2-amino acids must be l (-) form2-amino acids must be l (-) form Sugars d (+) formSugars d (+) form

Thalidomide in 1960’sThalidomide in 1960’s

For morning sicknessFor morning sickness One enantiomer causes One enantiomer causes

malformations in the fetusmalformations in the fetus

Do question 10-11Do question 10-11 Do questions 28-30 page 415 for HWDo questions 28-30 page 415 for HW Do questions 12-17 on page 74 of Do questions 12-17 on page 74 of

your study guideyour study guide Do questions 13-20 pages 416-418 in Do questions 13-20 pages 416-418 in

your textbookyour textbook