Реакция #159258

Уравнение реакции

ammonium chloride

5,6-dihydro-7H-pyrrolo[1,2-c]imidazol-7-one

6-Bromo-2-naphthoic acid

n-butyllithium

→

title compound

Выход 12.2%

6-(7-hydroxy-6,7-dihydro-5H-pyrrolo[1,2-c]imidazol-7-yl)-2-naphthoic acid

Выход 12.2%

Растворители

ethyl acetate

THF

THF

hexane

Условия реакции

Обработка

1. 1
   workup.ADDITIONwas added dropwise at −95° C. or below over 5 min
2. 2
   Температураthe mixture was cooled to −100° C. again
3. 3
   workup.STIRRINGAfter stirring at the same temperature for 30 min
4. 4
   Температураthe temperature was raised to −70° C. over 30 min
5. 5
   Другоеto quench
6. 6
   Другоеthe reaction
7. 7
   workup.STIRRINGAfter stirring for 10 min
8. 8
   Другоеto partition the solution
9. 9
   ДругоеThe organic layer was removed
10. 10
    Концентрированиеthe aqueous layer was concentrated to dryness
11. 11
    ДругоеThe obtained residue was purified by flash column chromatography
12. 12
    workup.DISSOLUTIONthe object fraction was dissolved in methanol
13. 13
    КонцентрированиеThis solution was concentrated
14. 14
    workup.ADDITIONether was added to the precipitated powder
15. 15
    Фильтрацияthe powder was collected by filtration
16. 16
    Другоеdried

Методика

6-Bromo-2-naphthoic acid (1.51 g) was dissolved in dry THF (50 ml), and cooled to −100° C. in a liquid nitrogen/diethyl ether bath. Under stirring a solution (1.6M; 7.88 ml) of n-butyllithium in hexane was added dropwise at −95° C. or below over 5 min. After stirring at −100° C. for 30 min and at −80° C. for 10 min, the mixture was cooled to −100° C. again. A solution of 5,6-dihydro-7H-pyrrolo[1,2-c]imidazol-7-one (0.61 g) in dry THF (11 ml) was added dropwise at −90° C. or below over 5 min. After stirring at the same temperature for 30 min, the temperature was raised to −70° C. over 30 min, and saturated aqueous ammonium chloride solution (25 ml) was added to quench the reaction. After stirring for 10 min, ethyl acetate (50 ml) was added to partition the solution. The organic layer was removed and the aqueous layer was concentrated to dryness. The obtained residue was purified by flash column chromatography, and the object fraction was dissolved in methanol. This solution was concentrated, ether was added to the precipitated powder and the powder was collected by filtration and dried. The title compound (180 mg) was obtained as a colorless powder. The mother liquor was concentrated to give a residue (449 mg) containing the title compound.

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