Organic synthesis (A Level) · Síntese orgânica (A Level)
| English | Português |
|---|---|
| acyl chloride/əˈkɪl ˈklɔːraɪd/ | cloreto de acila |
| functional group/ˈfʌŋkʃənl ɡruːp/ | grupo funcional |
| diazonium salt/ˌdaɪəˈzəʊnɪəm sɒlt/ | sal de diazônio |
| reagent/rɪˈeɪdʒənt/ | reactivo |
| by-product/baɪ ˈprɒdʌkt/ | subproduto |
Designing a synthesis
- Like AS synthesis, you join up known reactions to build a target.
- Now you also have the reactions of arenes, phenol, amines, amides and acyl chlorides 酰氯.
- Identify the groups, use the map, plan backwards.
Projetando uma síntese
- Assim como na síntese AS, você conecta reações conhecidas para construir um alvo.
- Agora você também tem as reações de arenos, fenol, aminas, amidas e cloretos de acila 酰氯.
- Identifique os grupos, use o mapa, planeje de trás para frente.
A-Level synthesis planner · Planejador de síntese A-Level
Build a route by matching functional-group changes to reagents.
Planning an organic synthesis means choosing a sequence of reactions to convert a starting material into a target molecule.
Few steps and good yields are preferred.
Identifying functional groups 官能团
- decolourises bromine water with no catalyst (white precipitate) → a phenol or phenylamine (activated ring).
- reacts violently with cold water (HCl fumes) → an acyl chloride.
- purple colour with neutral $\text{FeCl}_3$ → a phenol.
A map of the A Level reactions
Identificando grupos funcionais 官能团
- descoloriza água brominada sem catalisador (precipitado branco) → um fenol ou fenilamina (anel ativado).
- reage violentemente com água fria (fumos de HCl) → um cloreto de acila.
- cor roxa com neutral $\text{FeCl}_3$ → um fenol.
Um mapa das reações do Nível A
A purple colour with neutral iron(III) chloride identifies a:
Neutral FeCl₃ gives a purple colour with phenols.
A compound that reacts violently with cold water, giving fumes of HCl, is a:
Acyl chlorides hydrolyse vigorously with water, releasing HCl.
Match each term to its meaning.
Each item links the term to its correct meaning.
The A Level reaction map
- aromatic chain: benzene → nitrobenzene → phenylamine → diazonium salt 重氮盐 → phenol / azo dye.
- acyl chain: carboxylic acid → acyl chloride → ester / amide.
- plus: amide/nitrile → amine ($\text{LiAlH}_4$); halogenoalkane → nitrile (KCN, +1 carbon).
Identification tests added at A Level
O mapa de reações do Nível A
- cadeia aromática: benzeno → nitrobenzeno → fenilamina → sal de diazônio 重氮盐 → fenol / corante azo.
- cadeia de acila: ácido carboxílico → cloreto de acila → éster / amida.
- mais: amida/nitrila → amina ($\text{LiAlH}_4$); haloalcano → nitrila (KCN, +1 carbono).
Testes de identificação adicionados no Nível A
Phenylamine reacting with HNO₂ below 10 °C gives:
Cold HNO₂ forms a diazonium salt, which can then make phenol or couple to an azo dye.
Ethanoyl chloride reacts with excess ammonia to form the amide ____.
The acyl group stays as CH₃CO– and –NH₂ replaces –Cl, giving CH₃CONH₂.
Replacing a halogen with –CN adds one carbon to the organic molecule.
The carbon in the cyanide group joins the carbon skeleton; count it when planning the product.
Which reagent reduces an amide to an amine?
LiAlH₄ is the reducing agent on the reaction map. FeCl₃ and bromine water are identification tests.
Planning and analysing
- plan by working backwards from the target; write each step's reagent 试剂 and conditions.
- analyse by stating each step's reaction type (electrophilic substitution, addition–elimination, oxidation, reduction…) and watching for by-products 副产物.
Plan backwards from the target, one disconnection at a time, until you reach the starting materials
Planejamento e análise
- planeje trabalhando de trás para frente a partir do alvo; escreva os reagentes 试剂 e condições de cada etapa.
- analise declarando o tipo de reação de cada etapa (substituição eletrofílica, adição-eliminação, oxidação, redução...) e prestando atenção aos subprodutos 副产物.
Planeje de trás para frente a partir do alvo, uma desconexão de cada vez, até chegar aos materiais de partida
The best way to plan a multi-step synthesis is to:
Working backwards finds which reaction makes the target, and from what, step by step.
You've got it
- tests: neutral FeCl₃ → purple (phenol); violent with cold water (acyl chloride); bromine water, no catalyst (phenol/phenylamine)
- map: benzene → nitrobenzene → phenylamine → diazonium → phenol/azo; acid → acyl chloride → ester/amide
- plan backwards from the target; analyse each step's reaction type and by-products
Entendeu?
- testes: FeCl₃ neutro → roxo (fenol); violento com água fria (cloreto de acila); água brominada, sem catalisador (fenol/fenilamina)
- mapa: benzeno → nitrobenzeno → fenilamina → diazônio → fenol/azo; ácido → cloreto de acila → éster/amida
- planeje de trás para frente a partir do alvo; analise o tipo de reação e subprodutos de cada etapa