Organic synthesis (A Level) · Síntesis orgánica (Nivel A)
| English | Español |
|---|---|
| acyl chloride/əˈkɪl ˈklɔːraɪd/ | cloruro de acilo |
| functional group/ˈfʌŋkʃənl ɡruːp/ | grupo funcional |
| diazonium salt/ˌdaɪəˈzəʊnɪəm sɒlt/ | sal diazonio |
| reagent/rɪˈeɪdʒənt/ | reactivo |
| by-product/baɪ ˈprɒdʌkt/ | subproducto |
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.
Diseño de una síntesis
- Al igual que en la síntesis del AS, conectas reacciones conocidas para construir un objetivo.
- Ahora también tienes las reacciones de arenos, fenol, aminas, amidas y cloruros de acilo.
- Identifica los grupos, utiliza el mapa, planifica hacia atrás.
A-Level synthesis planner · Planificador de síntesis Nivel A
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
Identificación de grupos funcionales
- decoloriza agua de bromo sin catalizador (precipitado blanco) → un fenol o fenilamina (anillo activado).
- reacciona violentamente con agua fría (humos de HCl) → un cloruro de acilo.
- color púrpura con neutral $\text{FeCl}_3$ → un fenol.
Un mapa de las reacciones del A Level
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
El mapa de reacciones del A Level
- cadena aromática: benceno → nitrobenceno → anilina → sal de diazonio → fenol / colorante azoico.
- cadena acilo: ácido carboxílico → cloruro de acilo → éster / amida.
- además: amida/nitrilo → amina ($\text{LiAlH}_4$); halogenuro de alquilo → nitrilo (KCN, +1 carbono).
Pruebas de identificación añadidas en el A Level
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
Planificación y análisis
- planificar trabajando hacia atrás desde el objetivo; escribir los reactivos y condiciones de cada paso.
- analizar indicando el tipo de reacción de cada paso (sustitución electrofílica, adición-eliminación, oxidación, reducción…) y prestando atención a los subproductos.
Planifica hacia atrás desde el objetivo, una desconexión a la vez, hasta llegar a las materias primas
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
Lo has entendido
- pruebas: FeCl₃ neutro → púrpura (fenol); reacción violenta con agua fría (cloruro de acilo); agua bromada, sin catalizador (fenol/fenilamina)
- esquema: benceno → nitrobenceno → fenilamina → diazonio → fenol/azo; ácido → cloruro de acilo → éster/amida
- planificar hacia atrás desde el objetivo; analizar el tipo de reacción y los subproductos de cada paso