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ChemicalBook CAS DataBase List (6R-cis)-3-(acetoxymethyl)-7-methoxy-8-oxo-7-(2-thienylacetamido)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid
35565-06-1

(6R-cis)-3-(acetoxymethyl)-7-methoxy-8-oxo-7-(2-thienylacetamido)-5-thia-1-azabicyclo[4.2.0]oct-2-ene-2-carboxylic acid synthesis

2synthesis methods
-

Yield:-

Reaction Conditions:

Stage #1: sodium cephalothinwith N-chloro-succinimide;methanesulfonic acid in methanol;dichloromethane at -65; for 3 h;
Stage #2: sodium methylate in methanol;dichloromethane; for 5 h;Temperature;

Steps:

1.1; 2.1; 3.1 Example 1

Step 1: In a 10L four-neck round bottom flask, add 6000ml of dichloromethane,450ml methanol and 627gCeftiofen, Cool down to -65 , add 105g methanesulfonic acid,A total of 241 g of chlorosuccinimide was slowly added in 8 batches and stirred for 3 h;The high-performance liquid phase was monitored until the reaction was complete. A methanol solution containing 132 g of sodium methoxide was added dropwise within 3 hours, and the stirring was continued for 2 hours. After the liquid phase monitoring reaction was completed, 19.5 g of sodium sulfite, 75 ml of acetic acid, and a saturated sodium chloride solution were added. 300ml, stir the reaction for 3 hours and raise the temperature to 0 ° C; adjust the pH to 2 with hydrochloric acid, separate the liquid, wash the organic layer with water, add cyclohexylamine solution to pH 6 dropwise, add 500ml of isopropyl ether, and stir at 0 ° C for 2h to precipitate white crystals , Filtered, dried to get7-methoxycefathiophene.

References:

CN110396105,2019,A Location in patent:Paragraph 0133; 0134; 0138; 0139; 0143; 0144

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