3-tert-Butyltoluene → 1-(Bromomethyl)-3-tert-butylbenzene

Beteiligte Stoffe

Reaktionsschritte

Dissolve 3-tert-butyltoluene (0.5 mL, 2.9 mmol) in carbon tetrachloride (20 mL). Add NBS (530 mg, 3 mmol) and irradiate the reaction mixture with a 250 watt sun-lamp with simultaneous heating to reflux for 1 h. Cool to ambient temperature, filter, and concentrate filtrate to dryness to give crude 1-bromomethyl-3-tert-butylbenzene. Dissolve crude 1-bromomethyl-3-tert-butylbenzene (600 mg) in anhydrous DMF. Add portion wise sodium azide (260 mg, 4 mmol) and stir at room temperature for 2 h. Pour the mixture into water (250 mL), extract with EtOAc (3×50 mL), wash combined organic extracts with brine, dry over MgSO4, filter and evaporate solvent to give crude 1-azidomethyl-3-tert-butylbenzene, that was used without further purification. Dissolve crude 1-azidomethyl-3-tert-butylbenzene in methanol containing 10% Pd/C (75 mg) at 5° C., and stir the resulting slurry under 1 atm H2 for 1 h. Filtrate, concentrate in vacuo and purify by chromatography on silica gel eluting sequentially with hexane/EtOAc (4:1 and 1:1), EtOAc, methanol and 2M ammonia in methanol to give the title compound (255 mg, 53% overall). MS (ES+) m/z: 164 (M+H)+.

Herkunft & Nachweise