Sodium borohydride → 7-Bromo-2-isopropyl-1H-indene

HRID 1987458Notes

Reaction equation

HRID 1987458 reaction equation
[Br:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]2[C:3]=1[CH2:4][CH:5]([CH:12]([CH3:14])[CH3:13])[C:6]2=O.C1COCC1.CO.[BH4-].[Na+]>O>[Br:1][C:2]1[CH:10]=[CH:9][CH:8]=[C:7]2[C:3]=1[CH2:4][C:5]([CH:12]([CH3:14])[CH3:13])=[CH:6]2

Participants

5

Reactant 3

HCID 4311764Sodium borohydrideHCID 21899815MeOH tetrahydrofuranHCID 221730192-Isopropyl-4-bromo-1-indanone

Product 1

HCID 598325187-Bromo-2-isopropyl-1H-indene

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 73.4 g (0.29 mol) of 4-bromo-2-isopropylindan-1-one in 530 ml of a mixture of THF-methanol (2:1, vol.), 22.0 g (0.58 mol) of NaBH4 was added in small portions while vigorously stirring for 2 h at 0° C. This mixture was stirred for 12 h at room temperature and then added to 600 ml of cold water. The organic layer was separated, the aqueous layer was extracted with 3×300 ml of methyl-tert-butyl ether. The combined organic fractions were dried over K2CO3 and then evaporated to dryness. The residue was dissolved in 1500 ml of toluene, and 2.0 g of p-TosOH was added. The resulting solution was refluxed for 2 h using a Dean-Stark trap to remove the water formed, and then it was passed through a short Silica Gel 60 column (40-63 um, d 100 mm, l 80 mm, eluent: hexanes). This column was additionally washed with 250 ml of toluene. The combined organic fractions were evaporated to dryness. The product was isolated by vacuum distillation (bp 128-132° C./4 mm Hg). Yield 57.8 g (84%).

Workup

  1. stirringThis mixture was stirred for 12 h at room temperature
  2. customThe organic layer was separated
  3. extractionthe aqueous layer was extracted with 3×300 ml of methyl-tert-butyl ether
  4. dry with materialThe combined organic fractions were dried over K2CO3
  5. customevaporated to dryness
  6. dissolutionThe residue was dissolved in 1500 ml of toluene
  7. addition2.0 g of p-TosOH was added
  8. temperatureThe resulting solution was refluxed for 2 h
  9. customto remove the water
  10. customformed
  11. washThis column was additionally washed with 250 ml of toluene
  12. customThe combined organic fractions were evaporated to dryness
  13. customThe product was isolated by vacuum distillation (bp 128-132° C./4 mm Hg)

Sources & evidence

ORD record
ord-417ee82386314a8495e695bc24e5a828
Source dataset
uspto-grants-2009_06
Patent number
US07550544B2

Reaction notes

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