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

HRID 129430Notes

Reaction equation

HRID 129430 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, arid 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. temperaturewas 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-2e80de3ed9a346f68c52671e060137b1
Source dataset
uspto-grants-1995_11
Patent number
US05468722

Reaction notes

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