Pyridine → 5,5,8,8-Tetramethyl-5,6,7,8-tetrahydro-1H-cyclopenta[b]naphthalene

HRID 1017162Notes

Reaction equation

HRID 1017162 reaction equation
[CH3:1][C:2]1([CH3:18])[C:14]2[C:6](=[CH:7][C:8]3[CH2:9][CH:10](O)[CH2:11][C:12]=3[CH:13]=2)[C:5]([CH3:17])([CH3:16])[CH2:4][CH2:3]1.N1C=CC=CC=1.C1(C)C=CC(S(Cl)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:16][C:5]1([CH3:17])[C:6]2[C:14](=[CH:13][C:12]3[CH:11]=[CH:10][CH2:9][C:8]=3[CH:7]=2)[C:2]([CH3:18])([CH3:1])[CH2:3][CH2:4]1

Participants

5

Reactant 3

HCID 1049PyridineHCID 73974-Toluenesulfonyl chlorideHCID 18402884HCID 18402884, compound

Product 1

HCID 184028545,5,8,8-Tetramethyl-5,6,7,8-tetrahydro-1H-cyclopenta[b]naphthaleneYield 60.9%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A 1 L round bottom flask fit with a magnetic stirrer, condenser, thermometer, and nitrogen inlet was charged with anhydrous toluene (7 mL, Aldrich), the crude 5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenz(f)indan-2-ol (31.0 g, 0145 mol), pyridine (31.6 mL, 0.39 mol, Aldrich), and p-toluenesulfonyl chloride (30.4 g, 0.16 mol, Aldrich). The mixture was heated to reflux and cooled for GC analysis periodically for a total reflux time of 2 hours. The reaction was then quenched in 5% HCl (250 mL) and extracted into diethyl ether (200 mL). The ether extract was washed with 5% HCl (200 mL), 5% aqueous sodium bicarbonate (until neutral to pH paper), Water (2×200 mL), and dried over anhydrous magnesium chloride. Removal of solvents by rotary evaporation gave 23.0 g of crude product which was purified by chromatography on silica gel (60 g silica gel/hexane eluent) to give 5,5,8,8-tetramethyl-5,6,7,8-tetrahydrobenz(f)indene (17.5 g, 92-99+% pure by GC). 1HNMR (CDCl3, 500 MHz) δ7.44 (s, 1H); 7.36 (s, 1H); 6.82 (br d, J=5.5 Hz, 1H); 6.47 (br d, J=5.5 Hz, 1H); 3.51 (s, 2H); 1.70 (s, 4H); 1.32 (s, 12H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux
  3. temperaturecooled for GC analysis periodically for a total reflux time of 2 hours
  4. customThe reaction was then quenched in 5% HCl (250 mL)
  5. extractionextracted into diethyl ether (200 mL)
  6. extractionThe ether extract
  7. washwas washed with 5% HCl (200 mL), 5% aqueous sodium bicarbonate (until neutral to pH paper), Water (2×200 mL)
  8. dry with materialdried over anhydrous magnesium chloride
  9. customRemoval of solvents
  10. customby rotary evaporation
  11. customgave 23.0 g of crude product which
  12. customwas purified by chromatography on silica gel (60 g silica gel/hexane eluent)

Sources & evidence

ORD record
ord-cf63db0a02c1486dab4d7aaae92a8a13
Source dataset
uspto-grants-2002_11
Patent number
US06479424B1

Reaction notes

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