Skip to results

Tools · Synthesis

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.

Press / to jump here from anywhere. Type to filter.

Grignard addition: phenylmagnesium bromide + benzaldehyde → diphenylmethanol

PhMgBr + Ph–CHO → [Ph2CH–OMgBr] →(H3O+) Ph2CH–OH

Textbook Grignard addition. Phenylmagnesium bromide (PhMgBr) attacks benzaldehyde's carbonyl carbon; aqueous acidic workup releases diphenylmethanol (benzhydrol). PhMgBr is bought as a 1 M or 3 M solution in anhydrous Et2O or THF — solid Grignards are not weighed. Reaction is run under N2 with rigorous water exclusion.

Conditions: Cool a flame-dried, N2-flushed flask to 0 °C. Charge anhydrous Et2O (~3 mL per mmol of benzaldehyde). Add benzaldehyde (1.0 equiv) by syringe; stir 5 min. Add PhMgBr (1.1 equiv, 1 M or 3 M solution in Et2O) dropwise over 10 min — exotherm; control addition rate to keep T < 5 °C. Warm to RT, stir 1–2 h. Workup — Quench cautiously with sat. NH4Cl (or 10 % HCl); extract with Et2O; wash organic with sat. NaHCO3 + brine; dry MgSO4. Concentrate. Recrystallise from hexane or hexane/EtOAc. White crystals; mp 65–67 °C.

Expected yield
75–92 %
Expected duration
1–2 h at RT after 0 °C addition

Mechanism reference ↗

Scale inputs

Anchor reagent + concentration

Total reactant moles divided by this concentration sets the solvent volume.

Anchor amount

Updates as you type · the URL captures every input.

Computed quantities

Keyboard shortcuts

/
Focus the reaction picker
r
Focus the Amount input
c
Copy the procedure to clipboard
p
Print this procedure
/ Ctrl +
Force a recompute
?
Show this help
Esc
Close this dialog

Single-key shortcuts only fire when no input has focus. The URL bar captures every input, so the calculation is always shareable.

Recent Searches

Acetone
Ethanol
Navigate
esc Close