تفاعل #62546

معادلة التفاعل

4-bromo-methyl-5-methyl-1,3-dioxolene-2-one

HCl

7-formamido-3-(1,2,4-thiadiazol-4-yl)thiomethyl-3-cephem-4-carboxylic acid

propylene oxide

→

title compound

(5-Methyl-2-oxo-1,3-dioxolen-4-yl)methyl 7-formamido-3-(1,2,4-thiadiazol-4-yl)thiomethyl-3-cephem-4-carboxylate

المذيبات

EtOAc

DMF

ظروف التفاعل

المعالجة

1. 1
   أخرىThe EtOAc layer was separated
2. 2
   غسيلwashed successively with aq HCl (pH 3) (70 ml×2), 10% K2HPO4 buffer (pH 7) (70 ml×2) and saturated aq NaCl (50 ml)
3. 3
   تجفيفThe EtOAc solution was dried (MgSO4)
4. 4
   تركيزconcentrated in vacuo
5. 5
   أخرىThe residue was triturated with ether (300 ml)
6. 6
   ترشيحthe resulting precipitate was filtered

الإجراء التجريبي

A suspension of 7-formamido-3-(1,2,4-thiadiazol-4-yl)thiomethyl-3-cephem-4-carboxylic acid (1.07 g, 3 mmole), KHCO3 (1.0 g, 10 mmole) and propylene oxide (1 ml) in DMF (5 ml) was cooled to 5° C. and treated with 4-bromo-methyl-5-methyl-1,3-dioxolene-2-one (0.87 g, 4.5 mmole). After stirring at 5° C. for 5 hr, the reaction mixture was poured into a mixture of aq HCl (pH 3) (70 ml) and EtOAc (250 ml). The EtOAc layer was separated and washed successively with aq HCl (pH 3) (70 ml×2), 10% K2HPO4 buffer (pH 7) (70 ml×2) and saturated aq NaCl (50 ml). The EtOAc solution was dried (MgSO4) and concentrated in vacuo. The residue was triturated with ether (300 ml) and the resulting precipitate was filtered to give the title compound ( 0.45 g).

المصدر