反应详情

Oxalyl chloride (0.37 ml.) was added to a solution of N,N-dimethylformamide (0.38 ml) in methylene chloride (10 ml) with stirring under nitrogen at -20°. After ten minutes with ice water cooling, the mixture was recooled to -20° and (Z)-2-cyclopropylmethoxyimino-2-(2-tritylaminothiazol-4-yl)acetic acid (1.94 g) was added and the solution was stirred with ice-water cooling for 10 minutes. The solution was recooled to -20° and added to a solution of (6R,7R)-7-amino-3-carbamoyloxymethylceph-3-em-4-carboxylic acid (1.09 g) in industrial methylated spirits (12 ml) and water (3 ml) containing triethylamine (2.4 ml) at -10° and with vigorous stirring. After five minutes, the solution was partitioned between water and methylene chloride. Dilute hydrochloric acid was added to adjust the aqueous layer to pH >2. The aqueous layer was extracted with more methylene chloride and the combined organic layers were washed with water, dried with magnesium sulphate and evaporated. The residue was triturated with diethyl ether to give the title compound (2.32 g); [α]D21 +15.88° (c 0.69, CHCl3); νmax (Nujol) 3540 to 3100 (NH, NH2, OH, and water), 1785 (β-lactam), 1720 (acid and carbamate) and 1683 and 1510 cm-1 (amide).

1. customwas recooled to -20°
2. customwas recooled to -20°
3. customthe solution was partitioned between water and methylene chloride
4. additionDilute hydrochloric acid was added
5. extractionThe aqueous layer was extracted with more methylene chloride
6. washthe combined organic layers were washed with water
7. dry with materialdried with magnesium sulphate
8. customevaporated
9. customThe residue was triturated with diethyl ether