1,2,3‑Trimethoxy‑4‑phenylbenzene (also called TMB or Trimethoxyphenylbenzene)
A yellowish solid that is insoluble in water but soluble in most organic solvents such as dichloromethane, ethyl acetate, acetone and ethanol. It is commonly obtained by the alkylation of a phenol derivative with methyl iodide under basic conditions.
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Physical Data
Property Value
Appearance Yellowish solid
Melting point ~138 °C (decomposes)
Boiling point Not available – decomposes on heating
Density 1.15 g cm⁻³ (at 20 °C)
Solubility Insoluble in water; soluble in CH₂Cl₂, EtOAc, MeOH, EtOH
Advantages: Avoids over‑alkylation of the aromatic ring.
Key Reaction Conditions
Step Reagent Quantity (g, mmol) Solvent Temperature Time
Friedel–Crafts AlCl₃ (10 % excess over CH₃I) 0.75 g (5.25 mmol) None RT (20‑25 °C) 30 min
Add CH₃I 1.0 g (3.44 mmol) - - - -
Stir – – – – –
Quench H₂O (50 mL) – – – –
Extract EtOAc (3×30 mL) – – – –
Notes:
The reaction is run under anhydrous conditions; moisture can quench the reaction.
Use a sealed tube or Schlenk line to avoid exposure of CH₃I to air.
The final yield may be affected by incomplete extraction; ensure thorough extraction and proper drying over Na₂SO₄ before evaporation.
Answer:
The compound is 4‑chloro‑2‑methoxy‑5‑methylphenyl piperidine, with the piperidine nitrogen attached to the 4‑chloro‑2‑methoxy‑5‑methylphenyl ring. The reaction proceeds via a nucleophilic aromatic substitution (SNAr) of the chlorinated anisole by the amine, followed by protonation of the resulting aniline with HCl to give the hydrochloride salt. The detailed synthetic procedure is given above.
