Intro To Synthesis

Question 1

How to make ethyl ethanoate with only ethanol

Answer 1

-heat under reflux with acidified potassium dichromate to make ethanoic acid
-heat under reflux with conc H2SO4 catalyse

Question 2

When designing a synthetic pathway what must be considered

Answer 2

-product yield
-reaction set up (catalysts, reagents,conditions)
-process involved (batch or continuous)
-hazards
-costs
-formation of isomers

Question 3

How to calculate empirical formula from combustion data

Answer 3

Burn in excess oxygen and pass through tube with water absorber (eg anhydrous CaCl2(s) ) and measure change in mass then pass through tube with carbon dioxide absorber (eg CaOH) and measure change in mass

Question 4

Substance used to absorb water

Answer 4

Calcium chloride

Question 5

Substance used to absorb carbon dioxide

Answer 5

Calcium hydroxide

Question 6

How to make alkane into halogenoalkane

Answer 6

UV light and halogen at room temp, free radical substitution

Question 7

Alkene to alkane

Answer 7

Hydrogen and nickel catalyst at 150C, electrophilic addition

Question 8

Alkene to halogenoalkane

Answer 8

Hydrogen halide, electrophilic addition

Question 9

How to make halogenoalkane into alkene

Answer 9

Heat with conc NaOH in ethanol, elimination reaction

Question 10

Halogenoalkane to amine

Answer 10

Heat with excess concentrated ammonia in sealed tube with ethanol, nucleophilic substitution

Question 11

Halogenoalkane to nitrile

Answer 11

Heat under reflux with KCN in ethanol, nucleophilic substitution

Question 12

Nitrile to amine 2 ways

Answer 12

-LiAlH4 in dry ether followed by dilute acid
-hydrogen and platinum catalyst heated to 150C
Reduction

Question 13

Halogenoalkane to alcohol

Answer 13

Heat with dilute aqueous NaOH, nucleophilic substitution

Question 14

Alcohol to halogenoalkene

Answer 14

With conc HX/ PCl5

Question 15

Alcohol into ketone

Answer 15

Heat under reflux with acidified K2Cr2O7, oxidation

Question 16

Ketone to alcohol

Answer 16

LiAlH4 in dry ether followed by dilute acid, reduction

Question 17

Alcohol to aldehyde

Answer 17

Heat with acidified K2Cr2O7 and distil product immediately, oxidation

Question 18

Aldehyde to alcohol

Answer 18

LiAlH4 in dry ether followed by dilute acid, reduction

Question 19

Ketone/aldehyde to hydroxynitrile

Answer 19

Dilute sulphuric acid and excess KCN, nucleophilic addition

Question 20

Alkene to dihalogenoalkane

Answer 20

Hydrogen halide

Question 21

Nitrile to carboxylic acid

Answer 21

Heat under reflux with dilute HCl (aq)/ dilute NaOH (aq) followed by dilute acid, hydrolysis

Question 22

Alkene into alcohol

Answer 22

Heat with steam and phosphoric acid at 300C and 60atm , hydration

Question 23

Alcohol to alkene

Answer 23

Heated with excess of concentrated phosphoric acid at 170C, elimination

Question 24

Carboxylic acid to ester

Answer 24

Heat with concentrated sulfuric acid and alcohol, condensation

Question 25

Ester to carboxylic acid

Answer 25

Acid hydrolysis, heat under reflux with dilute HCl (aq) / heat under reflux with dilute NaOH (aq) followed by dilute HCl, hydrolysis

Question 26

Acyl chloride to ester

Answer 26

Alcohol at room temp, nucleophilic addition/elimination

Question 27

Carboxylic acid to acyl chloride

Answer 27

PCl5 at room temp

Question 28

Acyl chloride to amide

Answer 28

Concentrated ammonia in water

Question 29

Aldehyde to carboxylic acid

Answer 29

Heat under reflux with acidified K2Cr2O7, oxidation

Question 30

Carboxylic acid to aldehyde

Answer 30

Reduce acid to primary alcohol by adding LiAlH4 in dry ether and adding water, then heat with acidified K2Cr2O7 and distil product immediately