Nitrogen → HCID 23433578, compound

Temperature

140 °C

To a flame dried 250 mL 3-necked rb flask equivuipped with a magnetic stir bar was added Ce(III)Cl.7 H2O (2.74 g, 7.35 mmol, 2 equiv). The flask was heated in a 140° C. oil bath under reduced pressure (~1 torr) for 2.5 h. The flask was cooled to rt and slowly filled with N2 g. The white powder was suspended in dry THF (30 mL), stirred at rt for 1 h and then cooled to -78° C. To the white suspension was added a 1.4 M solution of methyl lithium (MeLi) in Et2O (5.25 mL, 7.35 mmol, 2 equiv) by syringe. The dark yellow/brown solution stirred at -78° C. for 1 h and then 1-t-butoxycarbonyl-1,2,3,4-tetrahydro-7-methoxy-4-quinolone dissolved in 3 mL THF was added. The solution stirred at -78° C. for 3 h and was warmed to 0° C. for 2 h. The reaction did not go to completion and starting material was observed by TLC (silica gel, hexane/EtOAc, 3:1). The reaction was quenched with H2O (1 mL) and allowed to warm to rt. The solution was neutralized with sat NH4Cl solution (5 mL), extracted with EtOAc (3×100 mL), washed with brine (1×100 mL), dried over Na2SO4 and concentrated in vacuo to give a mix of the desired alcohol and starting material. The mixture was taken up in EtOAc and concentrated on Celite™ to give a free flowing powder which was purified via flash column chromatography (silica gel, hexanes/EtOAc, 3:1) to give 796 mg (74%) of the desired product as a vicious clear colorless oil. Data for 1-t-butoxycarbonyl-1,2,3,4-tetrahydro-4-hydroxy-4-methyl-7-methoxy-quinoline: Rf =0.20 (hexanes/EtOAc, 3:1); 1H NMR (400 MHz, CDCl3) 7.42 (d, J=8.7, 1 H), 7.33 (d, J=2.5, 1 H), 6.66 (dd, J=2.5, 8.6, 1 H), 3.98 (m, 1 H), 3.79 (s, 3 H, OCH3), 3.61 (m, 1 H), 1.98 (m, 2 H), 1.58 (s, 3 H), 1.53 (s, 9 H).

1. customTo a flame dried 250 mL 3-necked rb flask
2. customequivuipped with a magnetic stir bar
3. additionwas added Ce(III)Cl
4. temperatureThe flask was cooled to rt
5. temperaturecooled to -78° C
6. stirringThe dark yellow/brown solution stirred at -78° C. for 1 h
7. additionwas added
8. stirringThe solution stirred at -78° C. for 3 h
9. temperaturewas warmed to 0° C. for 2 h
10. customThe reaction was quenched with H2O (1 mL)
11. temperatureto warm to rt
12. extractionextracted with EtOAc (3×100 mL)
13. washwashed with brine (1×100 mL)
14. dry with materialdried over Na2SO4
15. concentrationconcentrated in vacuo
16. customto give
17. concentrationconcentrated on Celite™
18. customto give
19. customwas purified via flash column chromatography (silica gel, hexanes/EtOAc, 3:1)

ORD record

ord-408cc0cc92f142c2b484a3ca00ef4e35

Source dataset

uspto-grants-2000_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06093821