Reacción #550606

Ecuación de reacción

Phosphorus oxychloride

2-methoxyimino-3,3-diethoxy-4-bromobutyric acid

potassium dihydrogenphosphate

sodium phosphate

→

2-methoxyimino-3,3-diethoxy-4-bromobutyryl chloride

Disolventes

tetrahydrofuran

N,N-dimethylformamide

water

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.STIRRINGstirred at -20° to -10° C. for an hour
2. 2
   workup.STIRRINGstirred under ice-
3. 3
   Temperaturacooling at pH 6.1 for 2 hours
4. 4
   FiltraciónThe precipitates were collected by filtration
5. 5
   Lavadowashed with water
6. 6
   Otrodried

Procedimiento

Phosphorus oxychloride (1.24 ml) was added to a solution of dry N,N-dimethylformamide (1.01 ml) in dry tetrahydrofuran (2ml) at -20° C. and stirred at the same temperature for 30 minutes. To the solution was added 2-methoxyimino-3,3-diethoxy-4-bromobutyric acid (syn isomer, 3.3 g) at -20° C. and stirred at -20° to -10° C. for an hour. The resultant solution was added to a solution of potassium dihydrogenphosphate (3.63 g) and sodium phosphate (14.33 g) in water (1000 ml) and stirred under ice-cooling at pH 6.1 for 2 hours. The precipitates were collected by filtration, washed with water and dried to give 2-methoxyimino-3,3-diethoxy-4-bromobutyryl chloride (syn isomer, 3.0 g), mp. 33°-35° C.

Fuente