Hydrochloric Acid → 6-Bromo-5,8-dimethylthiochroman-4-ol

HRID 343867Notes

Reaction equation

HRID 343867 reaction equation
[CH3:1][C:2]1[C:11]([Br:12])=[CH:10][C:9]([CH3:13])=[C:8]2[C:3]=1[C:4](=[O:14])[CH2:5][CH2:6][S:7]2.[Cl-].[Na+].[BH4-].[Na+].Cl>ClCCl.CO>[CH3:1][C:2]1[C:11]([Br:12])=[CH:10][C:9]([CH3:13])=[C:8]2[C:3]=1[CH:4]([OH:14])[CH2:5][CH2:6][S:7]2

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 5234Sodium ChlorideHCID 4311764Sodium borohydrideHCID 152784955,8-Dimethyl-6-bromothiochroman-4-one

Product 1

HCID 234507086-Bromo-5,8-dimethylthiochroman-4-olYield 91.3%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 6344DichloromethaneSolvent

Procedure

100 ml of methanol and 30 ml of dichloromethane were added to 10 g (36.9 mmol) of 5,8-dimehyl-6-bromothiochroman-4-one. While the mixture was maintained at a temperature not exceeding 0° C. with a sodium chloride aqueous solution and an ice bath, 0.70 g (18.4 mmol) of sodium borohydride as a reducing agent was gradually added. The mixture was allowed to react at room temperature for 3 hours, and then the reaction mixture was poured into a 5% hydrochloric acid aqueous solution and extracted with dichloromethane. The resultant dichloromethane layer was dried over anhydrous sodium sulfate and concentrated to give 9.2 g (yield 91%) of 5,8-dimethyl-4-hydroxy-6-bromothiochroman (corresponding to compound of the formula (VI)).

Workup

  1. temperatureWhile the mixture was maintained at a temperature not
  2. additionwas gradually added
  3. customto react at room temperature for 3 hours
  4. extractionextracted with dichloromethane
  5. dry with materialThe resultant dichloromethane layer was dried over anhydrous sodium sulfate
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-cf58e0ee4b344f9a82a6bb87da59fedc
Source dataset
uspto-grants-1999_01
Patent number
US05863866

Reaction notes

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