Reacción #1474334

Ecuación de reacción

CaCl2

thionyl chloride

p-nitrophenol

trans-urocanic acid

→

p-Nitrophenyl trans-3-(1H-imidazol-4-yl)-2-propenoate

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroequipped with a drying tube
2. 2
   Otrois progressively brought to 140° C
3. 3
   ExtracciónA brown powder is extracted with CHCl3/MeOH (150 ml, 2:1)
4. 4
   Temperaturawhile heating
5. 5
   OtroThe undissolved material is separated by filtration
6. 6
   workup.ADDITIONthe filtrate is treated with active charcoal
7. 7
   ConcentraciónConcentration
8. 8
   workup.ADDITIONis added so as
9. 9
   Otroprecipitation of a solid (1.96 g; overall crude yield: 61%)
10. 10
    OtroThe latter is recrystallized from MeOH
11. 11
    Lavadothe product is washed with diethyl ether in order
12. 12
    Otroto remove any trace of p-nitrophenol
13. 13
    Otrogiving a crystalline white solid, M.p. 220°-222° C.

Procedimiento

2 ml (27.5 mmol) of freshly distilled thionyl chloride are added to a finely ground mixture of 1.51 g (10.8 mmol) of p-nitrophenol and 1.5 g (10.8 mmol) of trans-urocanic acid in a round-bottomed flask equipped with a drying tube containing CaCl2. The mixture is progressively brought to 140° C. After 4 h, the mixture is slowly cooled to room temperature. A brown powder is extracted with CHCl3/MeOH (150 ml, 2:1) while heating. The undissolved material is separated by filtration and the filtrate is treated with active charcoal. Concentration is carried out under vacuum and diethyl ether is added so as to induce precipitation of a solid (1.96 g; overall crude yield: 61%). The latter is recrystallized from MeOH and the product is washed with diethyl ether in order to remove any trace of p-nitrophenol, giving a crystalline white solid, M.p. 220°-222° C.

Fuente