Advanced Chemistry Engine v3.0

Organic Reaction Predictor

Predict products, mechanisms, and reaction types for any organic transformation using advanced rule-based logic covering all 118 elements, their oxidation states, ionic forms, and coordination chemistry.

118 Elements Covered
42+ Reaction Types
300+ Reagent Patterns
Formula Resolver + 9 Modules
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Organic Reactions — Definitions & Core Formulas

Foundational theory every chemist must know

What is an Organic Reaction?

An organic reaction is any chemical transformation involving organic compounds (those containing carbon–hydrogen bonds). These reactions involve breaking and forming covalent bonds through well-defined mechanistic pathways governed by electron movement, orbital overlap, and thermodynamics.

What is a Reaction Mechanism?

A reaction mechanism is a step-by-step description of how a reaction proceeds — showing which bonds break, which bonds form, the sequence of intermediates (carbocations, carbanions, radicals), and the transition states involved at each step.

Nucleophile vs. Electrophile

A nucleophile is an electron-rich species that donates electrons to form bonds (e.g., OH⁻, NH₃, CN⁻). An electrophile is an electron-deficient species that accepts electrons (e.g., carbocations, carbonyl carbons, halogens).

Thermodynamics vs. Kinetics

Thermodynamic control favors the most stable product (ΔG most negative). Kinetic control favors the fastest-forming product (lowest activation energy, Ea). Temperature and reaction time determine which regime dominates.

⬡ KEY FORMULAS & EQUATIONS

Gibbs Free Energy
ΔG = ΔH − TΔS
Determines reaction spontaneity. ΔG < 0 = spontaneous (exergonic)
Arrhenius Equation
k = A·e^(−Ea/RT)
Relates rate constant k to activation energy Ea and temperature T
Equilibrium Constant
Keq = [Products]/[Reactants]
Ratio of product to reactant concentrations at equilibrium
Henderson-Hasselbalch
pH = pKa + log([A⁻]/[HA])
Critical for predicting protonation states and nucleophilicity
SN2 Rate Law
Rate = k[RX][Nu⁻]
Bimolecular; depends on both substrate and nucleophile concentration
SN1 Rate Law
Rate = k[RX]
Unimolecular; depends only on substrate; carbocation intermediate
Oxidation State Rule
Σ(ox. states) = charge
Sum of all oxidation numbers equals the total charge of the species
Hückel's Rule
4n + 2 π electrons
Aromaticity criterion (n = 0,1,2,...). Stabilizes cyclic conjugated systems
Markovnikov's Rule
H⁺ adds to less-sub. C
In HX addition to alkenes, H adds to the carbon with more H atoms
Beer-Lambert Law
A = εcl
Links absorbance (A) to concentration (c) via molar absorptivity (ε)
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Organic Reaction Predictor Calculator

Enter reactant, reagent & conditions — get full prediction with mechanism

🌡 Room Temp.
🔥 Heat / Δ
⚡ Acidic (H⁺)
🔵 Basic (OH⁻)
🧪 Anhydrous
💧 Aqueous
☀ UV / hν
⬆ Pressure
⚙ Catalyst
❄ Low Temp.
⚛ Radical
🛡 Inert Atm.
PREDICTION OUTPUT
Enter a reactant + reagent and click PREDICT

Composition Identifier

Composition, Oxidation, and scientific notation

Results Will Appear Here
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Classification of Organic Reactions

All major reaction categories with examples

Reaction Type Class Key Reagents Example Conditions
SN2SubstitutionStrong Nu⁻ (NaOH, NaCN, NaN₃)CH₃Br + OH⁻ → CH₃OH + Br⁻Polar aprotic, 1° substrate
SN1SubstitutionWeak Nu (H₂O, ROH)(CH₃)₃CBr + H₂O → (CH₃)₃COHPolar protic, 3° substrate
E2EliminationStrong base (KOH/EtOH)CH₃CH₂Br + KOH → CH₂=CH₂Conc. base, heat
E1EliminationWeak base, heat(CH₃)₃CBr →Δ (CH₃)₂C=CH₂Dilute base, high T
Electrophilic AdditionAdditionHX, X₂, H₂SO₄CH₂=CH₂ + HBr → CH₃CH₂BrRoom temp, Markovnikov
Nucleophilic AdditionAdditionRMgX, LiAlH₄, NaBH₄RCHO + RMgBr → RR'CHOHAnhydrous, then H₂O work-up
Electrophilic Aromatic Sub. (EAS)SubstitutionHNO₃/H₂SO₄, X₂/FeBr₃C₆H₆ + HNO₃ → C₆H₅NO₂Acid catalyst
Nucleophilic Acyl Sub.SubstitutionROH, RNH₂, H₂ORCOCl + ROH → RCOOR'Base, anhydrous
Aldol CondensationAdditionNaOH (cat), enol/enolate2CH₃CHO → CH₃CH(OH)CH₂CHOAqueous base, low T
Claisen CondensationAdditionNaOEt, ester enolate2RCOOEt → RCOCHRCOOEtEtOH/NaOEt
Oxidation (Primary Alcohol)OxidationKMnO₄, PCC, CrO₃RCH₂OH → RCHO or RCOOHAcidic/neutral
Reduction (Carbonyl)ReductionLiAlH₄, NaBH₄, H₂/PdRCHO → RCH₂OHAnhydrous THF
Diels-AlderCycloadditionDiene + dienophileButadiene + ethylene → cyclohexeneThermal, [4+2]
Grignard ReactionAdditionRMgX in dry etherRMgBr + RCHO → RR'CHOHAnhydrous, then H₃O⁺
Fischer EsterificationSubstitutionH₂SO₄ (cat), ROHRCOOH + R'OH ⇌ RCOOR' + H₂OAcid cat., reflux, equil.
Wittig ReactionAdditionPh₃P=CR₂ (ylide)RCHO + Ph₃P=CH₂ → RCH=CH₂Anhydrous, base
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How to Use the Calculator

Step-by-step guide with logic explanations and real examples

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The predictor uses a rule-based expert system that matches your input against a comprehensive database of reaction patterns, element properties, and mechanistic rules. The more specific your input, the higher the prediction confidence.
01

Enter the Reactant

Type the starting organic compound using its IUPAC name, common name, molecular formula, or SMILES notation. The smart parser will normalise all formats.

Examples: "ethanol" · "CH₃CH₂OH" · "CCO" · "2-bromopropane"

Tip: Use SMILES for precise structures (e.g., C(=O)c1ccccc1 for benzaldehyde).

02

Specify the Reagent

Enter the reagent or reagent mixture. You can use element symbols, compound formulas, or common lab names. Separate multiple reagents with commas.

Examples: "NaOH" · "HBr" · "LiAlH4, then H3O+" · "Br2/CCl4"

The engine recognises 300+ reagent patterns including organometallics, Lewis acids, and transition metal catalysts.

03

Select Reaction Conditions

Click one or more preset condition buttons (heat, acidic, UV, etc.) or type a custom condition. Conditions are critical — the same reactant + reagent can give different products under different conditions!

Example: Alcohol + H₂SO₄ → Alkene (heat) vs → Ether (lower T)

You can combine conditions: "Heat + acidic" will trigger dehydration logic.

04

Read the Prediction Output

The output panel shows: Product(s), Reaction Type, Mechanism (step-by-step), SMILES/Structure, and a confidence score. Each field is colour-coded.

Try: CH₃CH₂Br + NaOH + (aqueous) → CH₃CH₂OH [SN2 mechanism]
05

Use the Smart Parser for Concentration / Notation

Enter concentrations, scientific notation, or molecular expressions in the parser to convert them. Supports subscript/superscript normalisation and molarity calculations.

Examples: "2.5×10⁻³ M HCl" · "H2SO4" · "3mol CH3COOH"
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Aspects & Uses of Organic Reactions

Why organic chemistry drives science and industry

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Pharmaceuticals
Synthesis of drug molecules (aspirin, paracetamol, penicillin) via multi-step organic transformations including acylation, reduction, and cyclization.
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Polymer Chemistry
Addition and condensation polymerisation of monomers (ethylene → polyethylene; nylon via diamine + diacid condensation).
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Agrochemicals
Herbicide and pesticide synthesis. Glyphosate, DDT, organophosphates all derive from nucleophilic substitution and condensation reactions.
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Materials Science
Organic semiconductors, OLEDs, and conductive polymers synthesised via cross-coupling (Suzuki, Heck, Buchwald-Hartwig) reactions.
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Biochemistry
Enzyme-catalysed organic reactions (transaminase, hydrolase, oxidoreductase) underpin all metabolic pathways including glycolysis and the TCA cycle.
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Petrochemicals
Catalytic cracking, reforming, and isomerisation reactions of petroleum fractions produce fuels, lubricants, and feedstock chemicals.
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Dyes & Pigments
Azo coupling reactions between diazonium salts and aromatic amines/phenols produce vivid synthetic dyes used in textiles and inks.
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Green Chemistry
Atom-economical reactions (Diels-Alder, metathesis) and biocatalysis minimise waste and energy, central to sustainable chemical manufacturing.
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Reaction Mechanism — Step-by-Step Process

Illustrated with SN2, E2, EAS & Grignard examples

Solved Examples with Full Workings

12 detailed worked examples across major reaction classes

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Applying Organic Reactions in Scientific Research

Real-world research scenarios where reaction prediction is essential

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Drug Discovery & Medicinal Chemistry
Predict synthetic routes to drug candidates. Amide bond formation (HATU coupling), ring closure reactions, and chiral centre control are critical in lead optimisation campaigns.
RNH₂ + RCOOH → [HATU] → RCONHR (amide bond)
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Energy Storage Materials
Cross-coupling reactions (Suzuki-Miyaura, Stille) synthesise conjugated polymer backbones for organic photovoltaics and battery electrodes with tunable HOMO-LUMO gaps.
ArBr + ArB(OH)₂ → [Pd cat.] → Ar-Ar
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Natural Product Synthesis
Total synthesis of complex molecules (taxol, morphine, quinine) requires orchestrated sequences of Diels-Alder, aldol, and oxidation/reduction steps guided by retrosynthetic analysis.
Retrosynthesis: Target ← Synthon A + Synthon B
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Chemical Biology
Bioorthogonal reactions (click chemistry: azide-alkyne cycloaddition via Cu(I) or SPAAC) label biomolecules in living systems without interfering with biochemistry.
R-N₃ + R'-C≡CH → [CuI] → triazole product
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Process Chemistry & Scale-up
Predict reaction outcomes under high-pressure, continuous-flow, or solvent-free conditions. Grignard and Wittig reactions are adapted for industrial scale with modified temperature/solvent profiles.
Flow chemistry: safer handling of RLi, DIBAL, BuLi
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Green & Sustainable Chemistry
Ring-closing metathesis (Grubbs catalyst), organocatalysis, and enzymatic reactions achieve high atom-economy and E-factor scores crucial for sustainable industrial synthesis.
RCH=CH₂ + CH₂=CHR → [Grubbs] → cycloalkene + C₂H₄

Frequently Asked Questions

16 detailed answers about organic reactions and this tool