Water → 5-Bromo-2-methyl-1,2,6,7,8,9-hexahydro-3h-cyclopenta[a]naphthalen-3-one

HRID 269446Notes

Reaction equation

HRID 269446 reaction equation
[CH3:1][CH:2]1[CH2:14][C:5]2=[C:6]3[C:11](=[CH:12][CH:13]=[C:4]2[C:3]1=[O:15])[CH2:10][CH2:9][CH2:8][CH2:7]3.[Al+3].[Cl-].[Cl-].[Cl-].[Br:20]Br.O>C(Cl)Cl>[Br:20][C:12]1[CH:13]=[C:4]2[C:3](=[O:15])[CH:2]([CH3:1])[CH2:14][C:5]2=[C:6]2[C:11]=1[CH2:10][CH2:9][CH2:8][CH2:7]2

Participants

6

Reactant 4

HCID 962WaterHCID 24408BromineHCID 6451240Aluminum(III) ChlorideHCID 158422452-Methyl-1,2,6,7,8,9-hexahydro-3h-cyclopenta[a]naphthalen-3-one

Product 1

HCID 586921155-Bromo-2-methyl-1,2,6,7,8,9-hexahydro-3h-cyclopenta[a]naphthalen-3-one

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Procedure

In a three-necked round-bottom 500 ml flask equipped with a reflux condenser, dropping funnel with pressure-equalizing, and mechanical stirrer a solution of 55.0 g (0.275 mol) of 2-methyl-1,2,6,7,8,9-hexahydro-3H-cyclopenta[a]naphthalen-3-one in 50 ml of CH2Cl2 was added dropwise with vigorous stirring for 1 h at −10° C. to a suspension of 92 g (0.69 mol) of AlCl3 in 100 ml of CH2Cl2. This mixture was stirred additionally for 1 h at this temperature; then 14.2 ml (44.0 g, 0.275 mol) of bromine was added dropwise with vigorous stirring for 1 h. The resulting mixture was stirred for 2 h at −10° C. and then overnight at ambient temperature, and, then, it was poured on 1000 cm3 of cold water. The organic layer was separated, the aqueous layer was extracted with 3×200 ml of methyl-tert-butyl ether. The combined extract was washed with saturated aqueous Na2SO3 to eliminate bromine and with aqueous Na2CO3. It was then dried over K2CO3, and evaporated to dryness. Fractional distillation gave a yellowish liquid, b.p. 195-198° C./4 mm Hg. Yield 58.3 g (76%).

Workup

  1. customIn a three-necked round-bottom 500 ml flask equipped with a reflux condenser
  2. additionwas added dropwise
  3. stirringwith vigorous stirring for 1 h
  4. stirringThe resulting mixture was stirred for 2 h at −10° C.
  5. customThe organic layer was separated
  6. extractionthe aqueous layer was extracted with 3×200 ml of methyl-tert-butyl ether
  7. extractionThe combined extract
  8. washwas washed with saturated aqueous Na2SO3
  9. dry with materialIt was then dried over K2CO3
  10. customevaporated to dryness
  11. distillationFractional distillation
  12. customgave a yellowish liquid, b.p. 195-198° C./4 mm Hg

Sources & evidence

ORD record
ord-2cd29d286f9c4850ba73c009f7ea9e4e
Source dataset
uspto-grants-2008_11
Patent number
US07446216B2

Reaction notes

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