Reacción #47731

Ecuación de reacción

2,4-dihydroxy benzaldehyde

N-acetylglycine

sodium acetate

NaN3

NaNO2

KBr

→

3-azido-7-hydroxycoumarin

Disolventes

acetic anhydride

Condiciones de reacción

Tratamiento posterior

1. 1
   Temperaturawas refluxed
2. 2
   workup.ADDITIONThe reaction mixture was poured onto icde
3. 3
   Otroto give a yellow precipitate
4. 4
   FiltraciónAfter filtration
5. 5
   Lavadothe yellow solid washed with ice water before it
6. 6
   Temperaturawas refluxed in a solution of concentrated HCl and ethanol (2:1, 30 ml) for 1 hour
7. 7
   workup.ADDITIONice water was added
8. 8
   workup.ADDITIONto dilute the solution
9. 9
   TemperaturaThe solution was then cooled in an ice bath
10. 10
    workup.STIRRINGThe mixture was stirred for 5-10 minutes
11. 11
    workup.STIRRINGAfter stirring for another 15 minutes
12. 12
    Filtraciónthe resulting precipitate was filtered off
13. 13
    Lavadowashed with water
14. 14
    Otrodried under reduced pressure
15. 15
    Otroto afford a brown solid
16. 16
    Otro2.2 g (54% overall yield)

Procedimiento

A mixture of 2,4-dihydroxy benzaldehyde (2.76 g, 20 mmol), N-acetylglycine (2.34 g, 20 mmol), anhydrous sodium acetate (60 mmol) in acetic anhydride (100 ml) was refluxed under stirring for 4 hours. The reaction mixture was poured onto icde to give a yellow precipitate. After filtration, the yellow solid washed with ice water before it was refluxed in a solution of concentrated HCl and ethanol (2:1, 30 ml) for 1 hour, then ice water was added to dilute the solution. The solution was then cooled in an ice bath and NaNO2 (40 mmol) was added. The mixture was stirred for 5-10 minutes and NaN3 (60 mmol) was added in portions. After stirring for another 15 minutes, the resulting precipitate was filtered off, washed with water, and dried under reduced pressure to afford a brown solid: 2.2 g (54% overall yield). The product was pure enough for further reactions. 1H NMR (DMSO-d6, 300 MHz) δ 6.74 (d, J=2.2 Hz, 1H), 6.79 (dd, J=8.4. 2.2 Hz, 1H), 7.47 (d, J=8.5 Hz, 1H), 7.56 (s, 1H). 13C NMR (DMSO-d6, 75 MHz) δ 161.0, 158.0, 153.4, 128.7, 128.5, 121.8, 114.5, 112.0, 102.7. IR (KBr): 3296 (s), 2125 (vs), 1680 (s), 1620 (m), 1321 (s). EI-HRMS m/e calculated for M+ C9H5N3O3 203.0331; found 203.0326.

Fuente