Reacción #88613

Ecuación de reacción

benzyl chloroformate

Sodium hydride

3-bromo-9H-dipyrido[2,3-b;4′,3′-d]pyrrol-5-ol

→

title compound

Rendimiento 17.0%

3-Bromo-5-hydroxy-dipyrido[2,3-b;4′,3′-d]pyrrole-9-carboxylic acid benzyl ester

Rendimiento 17.0%

Disolventes

DMF

DMF

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturaa cooled
2. 2
   workup.ADDITIONOn complete addition the mixture
3. 3
   workup.STIRRINGstirred for 15 minutes
4. 4
   workup.STIRRINGstirring
5. 5
   workup.WAITcontinued for 18 hours
6. 6
   OtroThe solvent was evaporated
7. 7
   workup.ADDITIONthe resultant residue diluted with water
8. 8
   Extracciónextracted with dichloromethane (5×50 mL) and ethyl acetate (3×30 mL)
9. 9
   SecadoThe combined organic layer was dried over (Na2SO4)
10. 10
    Filtraciónfiltered
11. 11
    Otroevaporated
12. 12
    Otroto afford a residue
13. 13
    OtroThe resultant residue was purified by flash chromatography (silica, 12 g cartridge, ISCO, 0-7% methanol in dichloromethane)
14. 14
    OtroThe appropriate fractions were collected
15. 15
    Otroevaporated

Procedimiento

Sodium hydride (167 mg, 4.17 mmol) was added to a cooled (0° C.) mixture of 3-bromo-9H-dipyrido[2,3-b;4′,3′-d]pyrrol-5-ol (1.0 g, 3.79 mmol) in DMF (15 mL). On complete addition the mixture was stirred for 15 minutes then allowed to warm to ambient temperature and stirred for 15 minutes. A solution of benzyl chloroformate (610 mg, 3.6 mmol) in DMF (1 mL) was added and stirring continued for 18 hours. The solvent was evaporated and the resultant residue diluted with water and extracted with dichloromethane (5×50 mL) and ethyl acetate (3×30 mL). The combined organic layer was dried over (Na2SO4), filtered and evaporated to afford a residue. The resultant residue was purified by flash chromatography (silica, 12 g cartridge, ISCO, 0-7% methanol in dichloromethane). The appropriate fractions were collected and evaporated to afford the title compound as a light yellow solid (240 mg, 17%). LCMS (Method B): RT=4.54 min, M+H+=398/400. 1H NMR (400 MHz, DMSO-d6): 8.99 (s, 1H), 8.79 (d, J=2.4 Hz, 1H), 8.63 (d, J=2.4 Hz, 1H), 8.23 (s, 1H), 7.63 (d, J=7.5 Hz, 2H), 7.48-7.36 (m, 3H), 5.61 (s, 2H).

Fuente