反应详情

To a mixture of 3-isopropoxyphenyl acetic acid (3.79 g, 19.54 mmol) and α-aminomethyl-3,4-dimethoxybenzene-acetic acid ethyl ester hydrochloride (5.656 g, 19.54 mmol) in 150 ml of methylene chloride was added triethylamine (5.44 ml, 2.0 eq) and HBTU (8.15 g, 21.50 mmol). The mixture was stirred at room temperature overnight and then extracted with 3N hydrochloric acid and methylene chloride. The organic layer was washed with water and sodium bicarbonate solution. After the evaporation of solvents, an oil was obtained (10.20 g). This oil (10.2 g) was dissolved in 100 ml of methylene chloride. The solution was cooled in an ice bath and then phosphorus pentachloride (10.0 g, 47.96 mmol) was added. The mixture was stirred at room temperature overnight and then poured into ice. The mixture was extracted with methylene chloride. The organic layer was washed with concentrated sodium bicarbonate solution and then dried. After the evaporation of solvents, an oil was obtained. This oil (8.81 g, 21.43 mmol) was mixed with sulfur (755 mg, 23.6 mmol) and the mixture was put into an oil bath preheated to 165° C. and stirred at this temperature for 20 minutes. Then ethanol (100 ml) was added and the mixture was filtered. The filtrate was evaporated and the residue was suspended into ethyl acetate. The solid was removed by filtration and the filtrate was washed with sodium bicarbonate solution. After the evaporation of solvents, the residue was purified through a flash column chromatography using ethyl acetate and hexane (2/1 ratio) to give 1-(3-isopropoxybenzyl)-6,7-dimethoxyisoquinoline-4-carboxylic acid ethyl ester (4.40 g, 55% for 3 steps).

1. extractionextracted with 3N hydrochloric acid and methylene chloride
2. washThe organic layer was washed with water and sodium bicarbonate solution
3. customAfter the evaporation of solvents
4. customan oil was obtained (10.20 g)
5. temperatureThe solution was cooled in an ice bath
6. stirringThe mixture was stirred at room temperature overnight
7. additionpoured into ice
8. extractionThe mixture was extracted with methylene chloride
9. washThe organic layer was washed with concentrated sodium bicarbonate solution
10. customdried
11. customAfter the evaporation of solvents
12. customan oil was obtained
13. customthe mixture was put into an oil bath
14. custompreheated to 165° C.
15. stirringstirred at this temperature for 20 minutes
16. filtrationthe mixture was filtered
17. customThe filtrate was evaporated
18. customThe solid was removed by filtration
19. washthe filtrate was washed with sodium bicarbonate solution
20. customAfter the evaporation of solvents
21. customthe residue was purified through a flash column chromatography