Reacción #2286309

Ecuación de reacción

cyano-(2,6-dichloro-4-nitro-phenyl)-acetic acid tert-butyl ester

Cyano-(2,6-dichloro-4-nitrophenyl)-acetic acid tert-butyl ester

hydrochloric acid

sodium carbonate

tin(II) chloride dihydrate

tin(II) chloride dihydrate

→

(4-amino-2,6-dichloro-phenyl)-acetonitrile

Rendimiento 58.0%

Disolventes

ethanol

ethyl acetate

Condiciones de reacción

Tratamiento posterior

1. 1
   OtroThe reaction was fitted with a reflux condenser
2. 2
   Temperaturathe reaction was warmed to 110-115° C. where it
3. 3
   TemperaturaAt this time, the reaction was cooled to 25° C.
4. 4
   FiltraciónThe resulting thick mixture was filtered
5. 5
   Filtraciónthrough filter paper
6. 6
   Filtraciónvia vacuum filtration
7. 7
   Lavadowas washed with ethyl acetate until no material
8. 8
   OtroThe filtrate was then transferred to a separatory funnel
9. 9
   Otrowhere the resulting layers were separated
10. 10
    LavadoThe organics were washed consecutively with a 1N aqueous hydrochloric acid solution (1×250 mL)
11. 11
    SecadoThe organics were then dried with magnesium sulfate
12. 12
    Filtraciónfiltered
13. 13
    Concentraciónconcentrated under vacuum

Procedimiento

A solution of cyano-(2,6-dichloro-4-nitro-phenyl)-acetic acid tert-butyl ester (43) (78.69 g, crude) in ethanol (320 mL) at 25° C. was treated with concentrated hydrochloric acid (160 mL). The reaction was fitted with a reflux condenser and then was heated to 75° C. At this time, the resulting homogeneous solution was treated portion wise with tin(II) chloride dihydrate (225.64 g, 1.0 mol). Upon complete addition of the tin(II) chloride dihydrate, the reaction was warmed to 110-115° C. where it was stirred for 3 h. At this time, the reaction was cooled to 25° C. and then was diluted with ethyl acetate (1.5 L). The resulting solution was carefully neutralized with a saturated aqueous sodium carbonate solution (1.0 L). The resulting thick mixture was filtered through filter paper via vacuum filtration and was washed with ethyl acetate until no material was detected in the filtrate. The filtrate was then transferred to a separatory funnel where the resulting layers were separated. The organics were washed consecutively with a 1N aqueous hydrochloric acid solution (1×250 mL), a saturated aqueous sodium carbonate solution (1×250 mL), a 1N aqueous hydrochloric acid solution (1×250 mL), and a saturated aqueous sodium chloride solution (1×250 mL). The organics were then dried with magnesium sulfate, filtered, and concentrated under vacuum. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 80/20 hexanes/ethyl acetate) afforded (4-amino-2,6-dichloro-phenyl)-acetonitrile (44) (25.95 g, 58%) as a yellow solid; EL-HRMS m/e calcd for C8H6Cl2N2 (M+) 199.9908, found 199.9906. Exact Mass=199.9908; Molecular Weight=201.06.

Fuente