Sulfuric Acid → HCID 23043782, compound

Lithium diisopropylamide mono(tetrahydrofuran) (1.5M in cyclohexane; 3.6 ml) was added dropwise to a solution of 3,4-dihydro-1(2H)-dibenzothiophenone (1.0 g) in dry THF (30 ml) at -65°. The resultant solution was stirred at -65° for 1 h and 5-methyl-1-(triphenylmethyl)-1H-imidazole-4-carboxaldehyde (1.9 g) was then added. The reaction mixture was stirred for a further 1.5 h, whilst it was allowed to warm to 0°. The solution was quenched with acetic acid (6 ml) and the resultant suspension was treated with water (10 ml) and p-toluenesulphonic acid (10.2 g). The reaction mixture was heated at reflux for 17 h, added cautiously to 8% aqueous sodium bicarbonate (300 ml), and extracted with dichloromethane (2×120 ml). The combined organic extracts were dried and evaporated to give an oil which was heated at reflux in a mixture of trifluoroacetic acid (60 ml) and concentrated sulphuric acid (0.3 ml) for 40 min. The reaction mixture was concentrated in vacuo to ca. 10 ml, added cautiously to 8% aqueous sodium bicarbonate (300 ml) and the resultant suspension was extracted with dichloromethane (2×120 ml). The combined organic extracts were dried and evaporated to give a foam which was purified by FCC eluting with System A (100:5:0.5) to give the title compound (648 mg) as a solid, m.p. 220°-223°.

1. temperatureto warm to 0°
2. customThe solution was quenched with acetic acid (6 ml)
3. additionthe resultant suspension was treated with water (10 ml) and p-toluenesulphonic acid (10.2 g)
4. temperatureThe reaction mixture was heated
5. temperatureat reflux for 17 h
6. additionadded cautiously to 8% aqueous sodium bicarbonate (300 ml)
7. extractionextracted with dichloromethane (2×120 ml)
8. customThe combined organic extracts were dried
9. customevaporated
10. customto give an oil which
11. temperaturewas heated
12. concentrationThe reaction mixture was concentrated in vacuo to ca. 10 ml
13. additionadded cautiously to 8% aqueous sodium bicarbonate (300 ml)
14. extractionthe resultant suspension was extracted with dichloromethane (2×120 ml)
15. customThe combined organic extracts were dried
16. customevaporated
17. customto give a foam which
18. customwas purified by FCC
19. washeluting with System A (100:5:0.5)

ORD record

ord-ba7ed9d196bf409397f5491b112b137e

Source dataset

uspto-grants-1990_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04939144