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Reaction Scale Calculator

Pick a stored reaction, fix one reagent's amount, get every other reagent's quantity by stoichiometric equivalents. Solvent volume derived from your substrate concentration. Densities + molar masses come from our molecule database.

Reaction

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Claisen-Schmidt aldol: benzaldehyde + acetone → benzalacetone

Ph–CHO + CH3–C(=O)–CH3 → Ph–CH=CH–C(=O)–CH3 + H2O

Textbook aldol condensation. Acetone's α-carbon (deprotonated by aqueous NaOH) attacks benzaldehyde, then β-elimination dehydrates the aldol intermediate to give the E-enone benzalacetone (4-phenyl-3-buten-2-one). The 5-fold acetone excess is a kinetic control measure — without it, double-condensation to dibenzylideneacetone (DBA) competes.

Conditions: Dissolve NaOH (0.2 equiv) in 95 % EtOH/H2O (~3 mL per mmol benzaldehyde). Cool to 0–10 °C in an ice bath. Add benzaldehyde (1.0 equiv) followed by acetone (5.0 equiv) over 5 min with stirring. Warm to RT and stir 2–4 h until pale-yellow solid crystallises. Filter; wash crystals with cold water; recrystallise from ethanol. Yellow needles, mp 41–42 °C. Quench excess base with dilute HCl if filtrate is needed for analysis.

Expected yield: 70–85 %
Expected duration: 2–4 h at RT after 0–10 °C addition

Mechanism reference ↗

Anchor reagent — fix this amount, scale everything else Substrate concentration · M

Amount r Unit

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Reactants

Reactants for Claisen-Schmidt aldol: benzaldehyde + acetone → benzalacetone: stoichiometric quantities derived from the anchor amount.
Reagent	Equiv	Moles · mmol	Mass · g	Volume · mL
Benzaldehyde 100-52-7 · C7H6O	1.0	100.00	10.612	10.11
67-64-1 67-64-1 · C3H6O	5.0	500.00	29.040	36.76

Catalyst

Catalyst for Claisen-Schmidt aldol: benzaldehyde + acetone → benzalacetone: stoichiometric quantities derived from the anchor amount.
Reagent	Equiv	Moles · mmol	Mass · g	Volume · mL
Sodium Hydroxide 1310-73-2 · HNaO	0.2	20.00	0.800	0.38

Solvent

Solvent for Claisen-Schmidt aldol: benzaldehyde + acetone → benzalacetone: stoichiometric quantities derived from the anchor amount.
Reagent	Equiv	Moles · mmol	Mass · g	Volume · mL
Ethanol 64-17-5 · C2H6O	—	31177.85	1436.364	1818.18

Product

Product for Claisen-Schmidt aldol: benzaldehyde + acetone → benzalacetone: stoichiometric quantities derived from the anchor amount.
Reagent	Equiv	Moles · mmol	Mass · g	Volume · mL
122-57-6 122-57-6 · C10H10O density unavailable — volume not calculable.	1.0	100.00	14.619	—

Expected isolated yield

What you should actually weigh out of the recrystallisation flask, scaled from the limiting reactant via the canonical-procedure yield window.

Product: 122-57-6 122-57-6 · C10H10O
Theoretical max: 14.62 g (100.00 mmol)
Expected isolated · 70–85 % yield: 10.23 – 12.43 g

Stoichiometry: moles_X = (moles_anchor / equiv_anchor) × equiv_X. Mass = moles × MW; volume = mass / ρ. Solvent volume = total reactant moles ÷ substrate concentration.