Indene → 1-tert-Butyl-1H-indene
Reaction equation
[CH2:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[CH:2]1.[C:10](Br)([CH3:13])([CH3:12])[CH3:11]>[OH-].[K+]>[C:10]([CH:1]1[C:9]2[C:4](=[CH:5][CH:6]=[CH:7][CH:8]=2)[CH:3]=[CH:2]1)([CH3:13])([CH3:12])[CH3:11]Participants
4
Reactant 2
Product 1
Reagents, catalysts & solvents 1
Conditions
- Temperature
- 60 °C
Procedure
42.0 g of indene (technical grade, 94 % by GC, 39.5 g, 340 mmol), 50 % w aqueous KOH (308 g in 308 nL) and 15.8 g of Adogen (Aldrich, 34 mnuol) dissolved in 139.7 g of tert-butylbromide (1019.6 mmol) were introduced in this order, at room temperature, in a 1 L, jacketed glass reactor with mechanical stirrer (Buïchi). The organic phase turns green. The mixture is heated to 60° C. and vigorously stirred for two hours (a pressure build-up to 2.5 bar-g is observed) and then cooled to room temperature. Total reaction time is 3 h. The organic phase is extracted with technical hexane (3×200mL) and analyzed by GC. Conversion: 74.5% w of 3-tert-butyl-indene and 1.8% of 1-tert-butyl-indene, unreacted indene 13.7% w. The solution was evaporated under reduced pressure (rotovac) and the resulting dark brown viscous liquid was distilled at 1 mmHg, collecting the fraction boiling between 70 and 80° C. (40 g, 76.8% of 3-tert-butyl-indene and 19.5% of 1-tert-butyl-indene, no indene).