반응 #62775

반응 방정식

diisopropyl ether

sodium bicarbonate

benzhydryl 7-[2-(2-tritylaminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-1,2,4-triazin-3-yl)thiomethyl-3-cephem-4-carboxylate

anisole

trifluoroacetic acid

→

7-[2-(2-aminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-1,2,4-triazin-3-yl)thiomethyl-3-cephem-4-carboxylic acid

수율 84.6%

용매

methylene chloride

반응 조건

후처리

1. 1
   온도cooling
2. 2
   세척The separated aqueous layer was washed with ethyl acetate
3. 3
   추출extracted with a mixture of tetrahydrofuran and ethyl acetate
4. 4
   세척The extract was washed with a saturated aqueous solution of sodium chloride
5. 5
   기타dried
6. 6
   기타evaporated under reduced pressure
7. 7
   기타The residue was triturated in diethyl ether
8. 8
   여과collected by filtration

실험 절차

To a mixture of benzhydryl 7-[2-(2-tritylaminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-1,2,4-triazin-3-yl)thiomethyl-3-cephem-4-carboxylate (syn isomer) (1.20 g) and anisole (2.5 ml) in methylene chloride (2.5 ml) was added trifluoroacetic acid (5 ml) under ice-cooling. After being stirred for 30 minutes, the mixture was poured into diisopropyl ether (50 ml). The resultant mixture was adjusted to pH 7 with an aqueous solution of sodium bicarbonate. The separated aqueous layer was washed with ethyl acetate, acidified with 6N hydrochloric acid and extracted with a mixture of tetrahydrofuran and ethyl acetate. The extract was washed with a saturated aqueous solution of sodium chloride, dried and evaporated under reduced pressure. The residue was triturated in diethyl ether and collected by filtration to give 7-[2-(2-aminothiazol-4-yl)-2-difluoromethoxyiminoacetamido]-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-1,2,4-triazin-3-yl)thiomethyl-3-cephem-4-carboxylic acid (syn isomer) (600 mg).

출처