Module 6.1 synthesis

?
  • Created by: Abi9ai1
  • Created on: 20-11-19 13:28
Nitration of bezene- Reagents and conditions?
Concentrated sulfuric acid, Concentrated nitric acid, 50*C
1 of 62
Nitration of benzene- type of reaction?
Electrophilic substitutuion
2 of 62
Halogenation of benzene- Reagents and conditions?
Halogen carrier needed
3 of 62
Halogenation of benzene- type of reaction?
Electrophilic substitution
4 of 62
Friedel-crafts alkylation- Reagents and conditions?
Halogen carrier needed, room temperature.
5 of 62
Friedel-crafts alkylation- type of reaction?
Electrophilic substitution
6 of 62
Acylation -Reagents and conditions?
60*C for 30mins, reflux.
7 of 62
Acylation- type of reaction?
Electrophilic substitution
8 of 62
Partial oxidation of a primary alcohol-Reagents and conditions
Acidified potassium dichromate, distillation.
9 of 62
Partial oxidation of a primary alcohol- products?
Aldehyde
10 of 62
Complete oxidation of a primary alcohol-Reagents and conditions
Reflux, Acidified potassium dichromate or Tollens reagent to give a silver mirror
11 of 62
Complete oxidation of a primary alcohol- products?
Carboxylic acid
12 of 62
Colour change when primary alcohol is oxidated
orange to green
13 of 62
Oxidation of a secondary alcohol- reagents and conditions?
Reflux, acidified potassium dichromate.
14 of 62
Oxidation of secondary alcohol- products?
Ketone
15 of 62
Colour change when secondary alcohol is oxidated
orange to green
16 of 62
Oxidation of a tertiary alcohol- reaction?
No reaction, no colour change.
17 of 62
Reduction of an aldehyde- Reagents and conditions?
NaBH4, Small molecule (ethanol, water, HCN)
18 of 62
Reduction of an aldehyde- products?
Primary alcohol
19 of 62
Reduction of a ketone- Reagents and conditions?
HCN (generates CN-), acidic conditions, small molecules (ethanol, water, HCN)
20 of 62
Reduction of a ketone- products?
Hydroxynitrile
21 of 62
Alcohol + carboxylic acid- products?
Ester + water
22 of 62
Making a small ester - conditions?
Heated gently (80*C), sulfuric acid catalyst.
23 of 62
Making a large ester- conditions?
Reflux and then use fractional distillation to separate the ester.
24 of 62
Alcohol/phenol + acid anhydride- products?
Ester+ carboxylic acid
25 of 62
Hydrolysis of esters ( acidic conditions)- equation?
Ester + water -> carboxylic acid + alcohol
26 of 62
Hydrolysis of esters ( acidic conditions)- Reagents and conditions?
Reflux with hot aqueous acid
27 of 62
Hydrolysis of esters (alkaline conditions)- equation?
Ester + alkali -> carboxylate salt + alcohol
28 of 62
Hydrolysis of esters (alkaline conditions)- Reagents and conditions?
Reflux with hot aqueous alkali
29 of 62
Forming acyl chlorides- equation?
Carboxylic acid + SOCl2 -> acyl chloride + sulfur dioxide + hydrogen chloride
30 of 62
Acyl chloride to make esters- equation?
Acyl chloride + alcohol (or phenol) -> Ester + HCl
31 of 62
Acyl chloride to make carboxylic acids- equation?
Small acyl chloride (ethanoyl chloride) + water -> acid + HCl
32 of 62
Acyl chloride to make primary amide- equation?
Acyl chloride+ ammonia -> primary amide + ammonium chloride
33 of 62
Acyl chloride to make secondary amide- equation?
Acyl chloride + primary amide -> secondary amide + HCl
34 of 62
Nitration of benzene- mechanism?
.
35 of 62
Halogenation of benzene- mechanism?
.
36 of 62
Friedel-crafts alkylation- mechanism?
.
37 of 62
Acylation - mechanism?
.
38 of 62
Phenol + NaOH- mechanism?
.
39 of 62
Phenol + Halogen - mechanism?
.
40 of 62
What is benzene?
Naturally occurring aromatic hydrocarbon; liquid at room temp; C6H6; carcinogen.
41 of 62
What is Kekule's model of benzene
6 membered ring with alternating single and double bonds. 3 shorter double bonds and 3 longer single bonds. Double bonds keep breaking and reforming.
42 of 62
What are the problems with Kekule's model?
Benzene is resistant to addition reactions. Enthalpy of hydrogenation shows benzene to be more stable than predicted. All 6 carbon bonds are the same length.
43 of 62
Kekule's model of benzene diagram
.
44 of 62
Current model of benzene diagram
.
45 of 62
Describe the current model of benzene
Each of the 6 C atoms donates 1 electron from its P orbital. These electrons combine to form a ring of delocalised electrons above and below the plane. Electrons can move freely within the structure and don't belong to a single atom.
46 of 62
Why is benzene resistant to addition reaction?
Benzene is very stable as lots of energy is needed to disrupt the delocalisation.
47 of 62
What is Friedel-Crafts alkylation?
A H atom is replaced by an alkyl chain. A C-H bond is broken and a C-C bond is formed (alkylation). Difficult to do so a strong Lewis acid is used as a catalyst.
48 of 62
Why can multiple substitutions occur?
Each successive substitution makes the delocalised Pi electrons more nucleophilic so more susceptible to electrophilic attack.
49 of 62
What is an Acyl chloride?
Functional group RCOCl. Very reactive. Used in Friedel-Crafts reaction as halogen carrier. Catalyst (AlCl3).
50 of 62
How acidic is a phenol?
Phenol is a weak acid. It partially dissociates in water. Phenol will react with strong bases to form a salt and water.
51 of 62
Why is phenol more reactive than benzene?
Due to the p-orbital electrons from the oxygen in the OH group. These lone pair of electrons get drawn into the ring and add to the delocalised electrons. Increases electron density of ring (more nucleophilic).
52 of 62
What is a directing effect?
How a functional group directly attached to a ring affects which carbon atoms are likely to undergo substitution.
53 of 62
Nitration of Phenol with dilute HNO3
Single substitution. 2 products. Nitrate substituted on 2nd or 4th carbon. Room Temperature,
54 of 62
Nitration of Phenol with conc HNO3
Triple substitution. 1 product. Nitrate substituted on 2nd, 4th and 6th carbon. Room Temperature.
55 of 62
Electron withdrawing groups (NO2)
When NO2 is directly attached to the ring you see a 3-directing effect. NO2 group withdraws electrons from the Pi system. The rate of substitution is highest on 3rd carbon atom.
56 of 62
What is a nucleophile?
An electron pair acceptor.
57 of 62
What is Brady's reagent made of?
Methanol, sulfuric acid, and 2,4- DNP.
58 of 62
What is Brady's reagents results?
If an aldehyde or ketone is present a yellow/orange precipitate is formed. If an ester or carboxylic acid is present no precipitate is formed.
59 of 62
How do you determine whether we have an aldehyde or a ketone?
We take its melting point. The 2,4-DNP derivative precipitate is filtered and purified by recrystallisation. After drying we take the melting point and compare this result to a database of measured m.p. of 2,4-DNP derivatives and the b.p. of aldehyde
60 of 62
How is Tollens reagent made?
NaOH solution is added to silver nitrate solution until a brown precipitate is formed. Dilute ammonia is added dropwise until the brown precipitate redissolves.
61 of 62
Tollens reagent results?
Silver mirror is formed when there is an aldehyde. No reaction with ketone because it cannot be oxidised further.
62 of 62

Other cards in this set

Card 2

Front

Nitration of benzene- type of reaction?

Back

Electrophilic substitutuion

Card 3

Front

Halogenation of benzene- Reagents and conditions?

Back

Preview of the front of card 3

Card 4

Front

Halogenation of benzene- type of reaction?

Back

Preview of the front of card 4

Card 5

Front

Friedel-crafts alkylation- Reagents and conditions?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Reactions resources »