5371-94-8Relevant academic research and scientific papers
Preparation method of (RS)-methoxy cefoxitin
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Paragraph 0042-0051, (2019/10/01)
The invention discloses a preparation method of (RS)-methoxy cefoxitin, which is characterized by comprising the following steps: (1) taking thiophene as an initial raw material, n-heptane as a reaction solvent, reacting with trichloroacetaldehyde, and distilling under reduced pressure after the reaction; (2) reacting the product of the step (1) with methanol in the presence of alkaline substancesto prepare (RS)-alpha-methoxy-2-thiophenephenylacetic acid; (3) dissolving the (RS)-alpha-methoxy-2-thiophenephenylacetic acid in an organic solvent, adding a first organic base, stirring and clarifying, and dripping methanesulfonyl chloride or pivaloyl chloride for later use; adding HACA and an organic solvent into another reaction vessel, adding a second organic base, and stirring the mixture until the mixture is clarified for later use; slowly dripping a solution B into a solution A at below -30 DEG C; then dropwise adding chlorosulfonyl isocyanate to react to obtain white-like crystallinepowder; and (4) reacting the white-like crystalline powder with sodium methoxide to obtain a product. The purity of the product is high.
SUBSTITUTED DIHYDROPYRROLOPYRAZOLE COMPOUND
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Paragraph 1001-1003, (2017/09/12)
Provided is a compound represented by formula (I) or a pharmacologically acceptable salt thereof: wherein L1 is an optionally substituted C1-6 alkylene group or the like, L2 is a single bond or the like, L3 is a single bond or the like, R1, R2, and R3 are each independently an optionally substituted C1-4 alkyl group or the like, R4 is a hydrogen atom or the like, and R5 is a hydrogen atom or the like.
Process for preparing thiophene derivatives and thiophene derivatives obtained thereby
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, (2008/06/13)
Process for the preparation of a series of thiophene derivatives, from which 2-thiopheneacetic acid derivatives can easily be prepared, in high yields and selectivity by using substituted or unsubstituted thiophenes as the starting materials by easy operations. 2-Thiopheneacetic acid derivatives are very useful compounds as the chemical modifier of penicillin and cephalosporin. Novel compounds, i.e. α-arylthio-2-thiopheneacetic acids are also disclosed. These compounds are useful as the intermediates of the synthesis of 2-thiopheneacetic acids.
