Reacción #162982

Ecuación de reacción

(Z)—N-hydroxy-3-methyl-4-nitrobenzimidoyl chloride

ethyl propiolate

Et3N

→

title compound

Rendimiento 65.0%

Ethyl 3-(3-methyl-4-nitrophenyl)isoxazole-5-carboxylate

Rendimiento 65.0%

Disolventes

toluene

EtOAc

HCl

Condiciones de reacción

Tratamiento posterior

1. 1
   Otroof 30 min.
2. 2
   Otroat RT
3. 3
   TemperaturaThe reaction mixture was then heated at 80° C. for 16 hours
4. 4
   OtroReaction mass
5. 5
   LavadoThe organic layer was washed with water, brine
6. 6
   Secadodried over Na2SO4
7. 7
   Filtraciónfiltered
8. 8
   Concentraciónconcentrated in vacuo
9. 9
   OtroThe residue was purified by flash chromatography on silica gel
10. 10
    Lavadoeluting with 100% CHCl3

Procedimiento

To a solution of (Z)—N-hydroxy-3-methyl-4-nitrobenzimidoyl chloride (1.0 equiv.), ethyl propiolate (2.0 equiv.) in toluene was dropwise added Et3N over a period of 30 min. at RT and continued stirring at RT for 15 min. The reaction mixture was then heated at 80° C. for 16 hours. Reaction mass was diluted with EtOAc and neutralized with dilute HCl. The organic layer was washed with water, brine, dried over Na2SO4, filtered and concentrated in vacuo. The residue was purified by flash chromatography on silica gel, eluting with 100% CHCl3, to provide the title compound as creamish crystals (65%); 1H NMR (300 MHz, DMSO-d6) δ: 1.31-1.36 (t, J=7.0 Hz, 3H), 2.56 (s, 3H), 4.35-4.42 (q, 2H), 7.99-8.02 (m, 2H), 8.08 (s, 1H), 8.11 (m, 1H); IR (KBr) 3124, 3091, 2995, 2908, 1727, 1612, 1588, 1520, 1443, 1344, 1285, 1140, 1015, 950, 873, 771 cm−1.

Fuente