Pyridine → 5,6-Dimethyl-1H-indene

HRID 1017139Notes

Reaction equation

HRID 1017139 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][C:10]=1[CH3:11])[CH:7](O)[CH2:6][CH2:5]2.N1C=CC=CC=1.C1(C)C=CC(S(Cl)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][C:10]=1[CH3:11])[CH2:7][CH:6]=[CH:5]2

Participants

5

Reactant 3

HCID 1049PyridineHCID 73974-Toluenesulfonyl chlorideHCID 18402889HCID 18402889, compound

Product 1

HCID 897085,6-Dimethyl-1H-indeneYield 82.2%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A 1 L three-neck round bottom flask equipped with a condenser, mechanical stirrer, nitrogen inlet and a thermometer was charged with 5,6-dimethyl-1-indanol (41.25 g, 0.254 mol), toluene (250 mL), pyridine (250 mL, 3.1 mol), and p-toluenesulfonyl chloride (52.0 g, 0.273 mol). The mixture was heated to reflux and dehydration was monitored by GC. After 2.5 hours at reflux the reaction mixture was cooled, quenched in 5% HCl (1.2 L ice-water), and extracted with diethyl ether (500 mL). The organic phase was washed with 5% aqueous sodium bicarbonate, water, and then dried over anhydrous magnesium sulfate. Rotary evaporation followed by vacuum distillation (79° C./0.5 mm Hg) yielded 5,6-dimethylindene (30.1 g, 98+% purity by GC) as white crystalline solid (mp 34-35° C.). 1HNMR (CD2Cl2, 500 MHz) δ7.24 (s, 1H); 7.16 (s, 1H); 6.80 (m, 1H); 6.45 (m, 1H); 3.32 (s, 2H); 2.28 (s, 6H).

Workup

  1. customA 1 L three-neck round bottom flask equipped with a condenser, mechanical stirrer, nitrogen inlet
  2. temperatureThe mixture was heated
  3. temperatureto reflux
  4. temperatureAfter 2.5 hours at reflux the reaction mixture
  5. temperaturewas cooled
  6. customquenched in 5% HCl (1.2 L ice-water)
  7. extractionextracted with diethyl ether (500 mL)
  8. washThe organic phase was washed with 5% aqueous sodium bicarbonate, water
  9. dry with materialdried over anhydrous magnesium sulfate
  10. customRotary evaporation
  11. distillationfollowed by vacuum distillation (79° C./0.5 mm Hg)

Sources & evidence

ORD record
ord-80d1743ee64f4b20bde0d611ed9a2abf
Source dataset
uspto-grants-2002_11
Patent number
US06479424B1

Reaction notes

Loading…