Reacción #431848

Ecuación de reacción

(±)-9,10-difluoro-3-hydroxymethyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid ethyl ester

pyridine

3,5-dinitrobenzoyl chloride

→

(±)-9,10-difluoro-3-(3,5-dinitrobenzoyloxy)methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid ethyl ester

Rendimiento 75.2%

Disolventes

tetrahydrofuran

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.DISSOLUTIONThe suspension was once dissolved
2. 2
   Otroa colorless precipitate was then formed
3. 3
   TemperaturaAfter cooling
4. 4
   Filtraciónthe precipitate was collected by filtration
5. 5
   Lavadowashed with methanol and diethyl ether
6. 6
   Otrodried

Procedimiento

One gram of (±)-9,10-difluoro-3-hydroxymethyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid ethyl ester (I) and 500 mg of pyridine were suspended in 100 ml of anhydrous tetrahydrofuran (THF), and 1.6 g of 3,5-dinitrobenzoyl chloride was added thereto, followed by refluxing at 90° C. The suspension was once dissolved, and a colorless precipitate was then formed. The reaction was continued for 1.5 hours. After cooling, the precipitate was collected by filtration, washed with methanol and diethyl ether and dried to obtain 1.2 g of (±)-9,10-difluoro-3-(3,5-dinitrobenzoyloxy)methyl-7-oxo-2,3-dihydro-7H-pyrido[1,2,3-de][1,4]benzoxazine-6-carboxylic acid ethyl ester (II) as a colorless powder having a melting point of 240°-242° C.

Fuente