Hydrochloric Acid → HCID 10037723, compound

In a mixture of methylene chloride (60 ml) and methanol (80 ml) is dissolved methyl 7,8-dimethoxy-5-oxo-2,3,4,5-terahydro-1-benzoxepin-4-carboxylate obtained in Reference Example 11 (1.9 g). To the solution is added, while stirring, sodium borohydride (0.6 g) in limited amounts taking one hour. The reaction mixture is treated with dilute hydrochloric acid, followed by extraction with methylene chloride. The organic layer is washed with a small volume of a saturated aqueous saline solution, dried, and concentrated under reduced pressure. The residue is dissolved in methanol (5 ml), and to the solution is added a 2N aqueous solution of sodium hydroxide (20 ml). The mixture is stirred at room temperature for two hours. After addition of water (50 ml), the reaction mixture is washed with ether. The aqueous layer is acidified with dilute hydrochloric acid, and extracted with methylene chloride. The organic layer is washed with water, dried, and concentrated under reduced pressure. The residue is dissolved in dioxane (10 ml), to the solution is added concentrated hydrochloric acid (3 ml), and then the mixture is stirred for one hour at 90° C. After cooling, the reaction mixture is extracted with ethyl acetate. The organic layer is washed with water, dried, and concentrated under reduced pressure. The residue is recrystallized from ethyl acetate to afford 7,8-dimethoxy-2,3-dihydro-1-benzoxepin-4carboxylic acid as colorless needles (1.2 g), m. p. 209°-210° C.

1. additionTo the solution is added
2. extractionfollowed by extraction with methylene chloride
3. washThe organic layer is washed with a small volume of a saturated aqueous saline solution
4. customdried
5. concentrationconcentrated under reduced pressure
6. dissolutionThe residue is dissolved in methanol (5 ml)
7. additionto the solution is added a 2N aqueous solution of sodium hydroxide (20 ml)
8. stirringThe mixture is stirred at room temperature for two hours
9. additionAfter addition of water (50 ml)
10. washthe reaction mixture is washed with ether
11. extractionextracted with methylene chloride
12. washThe organic layer is washed with water
13. customdried
14. concentrationconcentrated under reduced pressure
15. dissolutionThe residue is dissolved in dioxane (10 ml), to the solution
16. additionis added concentrated hydrochloric acid (3 ml)
17. stirringthe mixture is stirred for one hour at 90° C
18. temperatureAfter cooling
19. extractionthe reaction mixture is extracted with ethyl acetate
20. washThe organic layer is washed with water
21. customdried
22. concentrationconcentrated under reduced pressure
23. customThe residue is recrystallized from ethyl acetate

ORD record

ord-29d973c01a2f4b799874c14065ac4ecc

Source dataset

uspto-grants-1990_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04937246