1,2,3-Tribromobenzene → 5-Bromo-9-isopropylidene-1,4-dihydro-1,4-methano-naphthalene

HRID 39409

Reaction equation

HRID 39409 reaction equation
Br[C:2]1[CH:7]=[CH:6][CH:5]=[C:4](Br)[C:3]=1[Br:9].[CH3:10][C:11]([CH3:17])=[C:12]1[CH:16]=[CH:15][CH:14]=[CH:13]1.C([Li])CCC.[Cl-].[NH4+]>C1(C)C=CC=CC=1>[Br:9][C:3]1[CH:2]=[CH:7][CH:6]=[C:5]2[C:4]=1[CH:13]1[C:12](=[C:11]([CH3:17])[CH3:10])[CH:16]2[CH:15]=[CH:14]1

Participants

6

Reactant 4

HCID 118421,2,3-TribromobenzeneHCID 25517Ammonium ChlorideHCID 1374671,3-Cyclopentadiene, 5-(1-methylethylidene)-HCID 178418339Butyllithium

Product 1

HCID 578576055-Bromo-9-isopropylidene-1,4-dihydro-1,4-methano-naphthaleneYield 66%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent2×

Procedure

To a stirred solution of 1,2,3-tribromo-benzene (4.34 g, 13.8 mmol) and 6,6-dimethylfulvene (2.38 g, assay 92.6%, 20.7 mmol) in dry toluene (60 ml) under a nitrogen atmosphere, 5.5 ml of a 2.5M toluene solution of n-butyllithium (14.5 mmol) were added dropwise at −5 to 0° C. within 10 minutes. After a further 10 minutes at 0° C. and 2 hours at ambient temperature, the reaction mixture was poured onto a saturated aqueous solution of ammonium chloride, extracted with ethyl acetate, washed with brine and water, dried over sodium sulphate and evaporated. Purification of the crude material on silca gel in hexane afforded 2.38 g of the desired product as a yellow oil (assay 84% by g.l.c., 55% yield). This reaction is also disclosed in WO 2007/068417.

Workup

  1. extractionextracted with ethyl acetate
  2. washwashed with brine and water
  3. dry with materialdried over sodium sulphate
  4. customevaporated
  5. customPurification of the crude material on silca gel in hexane

Sources & evidence

ORD record
ord-bc797f142524417b8cd33e6edb8dedf8
Source dataset
uspto-grants-2013_09
Patent number
US08524915B2

Linked notes

Loading…