Acetone → 6,7-Dichloro-5-hydroxy-alpha,alpha-dimethylbenzo[b]thiophene-2-methanol

HRID 370989

Reaction equation

HRID 370989 reaction equation
[Cl:1][C:2]1[C:3]([OH:12])=[CH:4][C:5]2[CH:9]=[CH:8][S:7][C:6]=2[C:10]=1[Cl:11].C([Li])CCC.C(Cl)(Cl)(Cl)Cl.C(=O)=O.[CH3:26][C:27]([CH3:29])=[O:28]>O1CCCC1.C(O)(=O)C.O>[Cl:1][C:2]1[C:3]([OH:12])=[CH:4][C:5]2[CH:9]=[C:8]([C:27]([CH3:29])([CH3:26])[OH:28])[S:7][C:6]=2[C:10]=1[Cl:11]

Participants

8

Reactant 4

HCID 180AcetoneHCID 132899976,7-Dichloro-1-benzothiophene-5-olHCID 86602444Carbontetrachloride dry-iceHCID 178418339Butyllithium

Product 1

HCID 132900426,7-Dichloro-5-hydroxy-alpha,alpha-dimethylbenzo[b]thiophene-2-methanol

Reagents, catalysts & solvents 3

HCID 176Acetic AcidSolventHCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of 6,7-dichloro-5-hydroxybenzo[b]thiophene in 28 ml of dried tetrahydrofuran at -28° is added 21 ml of 2.5M n-butyllithium, maintaining the temperature below -18°. Following the addition, the carbon tetrachloride-dry ice bath is replaced with an ice-water bath and the mixture is stirred at 0°-5° for about 4 hrs. A solution of 3.3 ml of acetone in 10 ml tetrahydrofuran is added dropwise. After stirring for one hr, the solution is poured onto 100 ml of water and acidified to pH=5-6 with glacial acetic acid. The acidic solution is extracted with ethyl acetate, washed, dried over anhydrous magnesium sulfate, filtered and the solvent is removed to give 3.84 g of 6,7-dichloro-5-hydroxy-α,α-dimethylbenzo[b]thiophene-2-methanol, mp 171°-173°.

Workup

  1. temperaturemaintaining the temperature below -18°
  2. additionthe addition
  3. stirringAfter stirring for one hr
  4. extractionThe acidic solution is extracted with ethyl acetate
  5. washwashed
  6. dry with materialdried over anhydrous magnesium sulfate
  7. filtrationfiltered
  8. customthe solvent is removed

Sources & evidence

ORD record
ord-7555993b5cea442e88037d537b6542ad
Source dataset
uspto-grants-1985_07
Patent number
US04528399

Linked notes

Loading…