Hydrochloric Acid → 6-Bromo-4-methoxy-5-methylthiochroman

HRID 1081996Notes

Reaction equation

HRID 1081996 reaction equation
[Br:1][C:2]1[C:3]([CH3:13])=[C:4]2[C:9](=[CH:10][CH:11]=1)[S:8][CH2:7][CH2:6][C:5]2=[O:12].[BH4-].[Na+].Cl.[CH2:17](Cl)Cl>CO>[Br:1][C:2]1[C:3]([CH3:13])=[C:4]2[C:9](=[CH:10][CH:11]=1)[S:8][CH2:7][CH2:6][CH:5]2[O:12][CH3:17]

Participants

6

Reactant 4

HCID 313Hydrochloric AcidHCID 6344DichloromethaneHCID 4311764Sodium borohydrideHCID 152784785-Methyl-6-bromothiochroman-4-one

Product 1

HCID 152784796-Bromo-4-methoxy-5-methylthiochroman

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Conditions

Temperature
0 °C

Procedure

4.4 Grams (0.017 mol) of 6-bromo-5-methylthiochroman-4-one was dissolved in 10 ml of methylene chloride and 10 ml of methanol. The solution was cooled to 0° C. with a salt water-ice bath. 0.32 Grams (0.0085 mol) of sodium borohydride was gradually added so that the temperature did not exceed 10° C. While the mixture was cooled with the ice bath, it was allowed to react for 1 hour. Then, the reaction mixture was poured into 100 ml of 5% hydrochloric acid, and extracted with methylene chloride. The methylene chloride layer was dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. Added to the resultant oil were 20 ml of methanol and 0.3 g of concentrated sulfuric acid, and the mixture was refluxed under heat for 2 hours. The reaction mixture was allowed to cool, poured into 200 ml of water and extracted with methylene chloride. The methylene chloride layer was dried over anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure to give 4.3 g of 6-bromo-4-methoxy-5-methylthiochroman as oil.

Workup

  1. customdid not exceed 10° C
  2. customto react for 1 hour
  3. extractionextracted with methylene chloride
  4. dry with materialThe methylene chloride layer was dried over anhydrous sodium sulfate
  5. distillationthe solvent was distilled off under reduced pressure
  6. additionAdded to the resultant oil
  7. temperaturethe mixture was refluxed
  8. temperatureunder heat for 2 hours
  9. temperatureto cool
  10. additionpoured into 200 ml of water
  11. extractionextracted with methylene chloride
  12. dry with materialThe methylene chloride layer was dried over anhydrous sodium sulfate
  13. distillationthe solvent was distilled off under reduced pressure

Sources & evidence

ORD record
ord-f987da2f149f4bc1825ab3bda0b4404a
Source dataset
uspto-grants-1996_12
Patent number
US05587484

Reaction notes

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