Hydrochloric Acid → HCID 10264893, compound

HRID 2108088Notes

Reaction equation

HRID 2108088 reaction equation
[CH3:1][O:2][C:3]1[C:4]([O:19][CH3:20])=[CH:5][C:6]2[S:12][CH2:11][CH2:10][CH:9]([C:13]([O:15]C)=[O:14])[C:8](=O)[C:7]=2[CH:18]=1.[BH4-].[Na+].Cl>CO.C(Cl)Cl>[CH3:1][O:2][C:3]1[C:4]([O:19][CH3:20])=[CH:5][C:6]2[S:12][CH2:11][CH2:10][C:9]([C:13]([OH:15])=[O:14])=[CH:8][C:7]=2[CH:18]=1

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 4311764Sodium borohydride2×HCID 10469837HCID 10469837, compound

Product 1

HCID 10264893HCID 10264893, compoundYield 63.4%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 6344DichloromethaneSolvent

Procedure

In a mixture solvent of methanol (50 ml) and methylene chloride (50 ml) is dissolved methyl 7,8-dimethoxy-5-oxo-2,3,4,5-tetrahydro-1-benzothiepin-4-carboxylate (11.4 g) obtained in Reference Example 8. To the solution is added sodium borohydride (2.1 g) in limited amounts taking 6 hours with stirring. Excess sodium borohydride is decomposed with dilute hydrochloric acid, followed by extraction with methylene chloride. The organic layer is washed with a small volume of saturated aqueous saline, dried, and concentrated under reduced pressure. The residue is dissolved in methanol (50 ml), to the solution is added a 7.5 N aqueous solution of sodium hydroxide (10 ml), and the mixture is stirred at room temperature for 1.5 hour. To the reaction mixture is added water. The mixture is acidified (pH 3) with dilute hydrochloric acid, followed by extraction with methylene chloride. The organic layer is concentrated under reduced pressure, and the concentrate is dissolved in dioxane (35 ml). To the solution is added 10N hydrochloric acid (7 ml), and the mixture is stirred at 50° C. for 30 minutes. The reaction mixture is cooled and diluted with water. Then precipitating crude crystals are collected by filtration, washed with water and dried, followed by recrystallization from methylene chloride-ether to give 7,8-dimethoxy-2,3-dihydro-1-benzothiepin-4-carboxylic acid as colorless prisms (6.5 g),

Workup

  1. customobtained in Reference Example 8
  2. extractionfollowed by extraction with methylene chloride
  3. washThe organic layer is washed with a small volume of saturated aqueous saline
  4. customdried
  5. concentrationconcentrated under reduced pressure
  6. dissolutionThe residue is dissolved in methanol (50 ml), to the solution
  7. additionis added a 7.5 N aqueous solution of sodium hydroxide (10 ml)
  8. stirringthe mixture is stirred at room temperature for 1.5 hour
  9. additionTo the reaction mixture is added water
  10. extractionfollowed by extraction with methylene chloride
  11. concentrationThe organic layer is concentrated under reduced pressure
  12. dissolutionthe concentrate is dissolved in dioxane (35 ml)
  13. additionTo the solution is added 10N hydrochloric acid (7 ml)
  14. stirringthe mixture is stirred at 50° C. for 30 minutes
  15. temperatureThe reaction mixture is cooled
  16. additiondiluted with water
  17. customThen precipitating crude crystals
  18. filtrationare collected by filtration
  19. washwashed with water
  20. customdried
  21. customfollowed by recrystallization from methylene chloride-ether

Sources & evidence

ORD record
ord-ef1ada236b284fd58aba23cce71467b0
Source dataset
uspto-grants-1990_06
Patent number
US04937246

Reaction notes

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