Chlorosuccinimide → HCID 14330450, compound

HRID 2414183Notes

Reaction equation

HRID 2414183 reaction equation
[CH3:1][O:2][C:3]1[C:12]2[S:11][CH2:10][CH:9](C(O)=O)[CH2:8][C:7]=2[CH:6]=[CH:5][CH:4]=1.ClN1C(=[O:22])CCC1=O>C(Cl)Cl>[CH3:1][O:2][C:3]1[CH:4]=[CH:5][CH:6]=[C:7]2[C:12]=1[S:11][CH2:10][C:9](=[O:22])[CH2:8]2

Participants

4

Reactant 2

HCID 31398ChlorosuccinimideHCID 14330455HCID 14330455, compound

Product 1

HCID 14330450HCID 14330450, compound

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a solution 8-methoxy-3,4-dihydro-2H[1]-benzothiopyran-3-carboxylic acid (10 g) in 200 ml of methylene chloride is added 6.2 g of N-chlorosuccinimide in portions. After 10 minutes 60 g of silica gel is added. The reaction mixture is stirred for 15 minutes, filtered through 40 g of silica gel eluting with ether/methylene chloride (1:1). The solvent is concentrated to 100 ml, 5 ml of triethylamine and 5 g of ethyl chloroformate are added. After concentration 5 g of sodium azide in 60 ml of DMF are added and the reaction mixture is stirred for 1 hour. After dilution with water the products are extracted with ether, the ether extract is dried and evaporated to dryness; 150 ml of 10% aqueous sulfuric acid is added and the reaction mixture is heated under reflux for 2 hours. The reaction mixture is extracted with ether, the ether extract is washed with dilute sodium bicarbonate solution, dried and evaporated to dryness. Crystallization from methanol affords 8-methoxythiochroman-3-one, melting point 60°.

Workup

  1. additionAfter 10 minutes 60 g of silica gel is added
  2. filtrationfiltered through 40 g of silica gel eluting with ether/methylene chloride (1:1)
  3. concentrationThe solvent is concentrated to 100 ml, 5 ml of triethylamine and 5 g of ethyl chloroformate
  4. additionare added
  5. additionAfter concentration 5 g of sodium azide in 60 ml of DMF are added
  6. stirringthe reaction mixture is stirred for 1 hour
  7. extractionAfter dilution with water the products are extracted with ether
  8. extractionthe ether extract
  9. customis dried
  10. customevaporated to dryness
  11. addition150 ml of 10% aqueous sulfuric acid is added
  12. temperaturethe reaction mixture is heated
  13. temperatureunder reflux for 2 hours
  14. extractionThe reaction mixture is extracted with ether
  15. extractionthe ether extract
  16. washis washed with dilute sodium bicarbonate solution
  17. customdried
  18. customevaporated to dryness
  19. customCrystallization from methanol

Sources & evidence

ORD record
ord-61fa960cf63f494d95cc85a425079a1f
Source dataset
uspto-grants-1988_01
Patent number
US04721787

Reaction notes

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