- Synthetic method of N-ethyl-2,3-dioxygen piperazine
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The invention relates to a synthetic method of N-ethyl-2,3-dioxygen piperazine, belonging to the technical fields of pharmaceutical and chemical industry. The synthetic method comprises the steps of preparing a mixed solution A from N-ethyl ethanediamine and absolute methanol, adding a catalyst and diethyl oxalate into absolute methanol, and uniformly stirring, so as to obtain a solution B. Compared with the prior art, the synthetic method of N-ethyl-2,3-dioxygen piperazine has the advantages that the raw materials are easily available, the operation is simple, conditions are mild, the quality is stable, and the energy consumption is low; and the synthetic method is environment-friendly and has very good industrial prospects and promotional values.
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Paragraph 0017-0041
(2017/12/28)
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- The Chemistry of Some 2-Aminothiazol-4-ylacetic Acid Derivatives and the Synthesis of Derived Penicillins
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The N-protected 2-aminothiazol-4-ylacetic acid derivatives (6), (11), (14), (16), (18), (26), (27), (30), (33), and (34) have been prepared.They are readily available by reaction of the corresponding 2-aminoethyl esters such as (1) with the appropriate acylating agents, generally giving a bis-carbamate of type (5), followed by saponification.The process is general for α-methylene, α-oximino, and α-aminosubstituents in the side-chain affording in the last case a route to differentially protected α-amino-α-(2-aminothiazol-4-yl)acetic acids such as (30).The optimum conditions for the acylations are described; the course of the saponification of the bis-carbamate esters is discussed and physical evidence for the structures of the derivatives is presented.The use of the protected acids (11) and (34) in the synthesis of the piperacillin analogue (38) is described.
- Hardy, Kenneth D.,Harrington, Frank P.,Stachulski, Andrew V.
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p. 1227 - 1236
(2007/10/02)
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- Novel penicillins and cephalosporins and process for producing the same
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Novel penicillins and cephalosporins and non-toxic salts thereof, which contain a mono- or di-oxo- or thioxo-piperazino(thio)carbonylamino group in molecule. These compounds are valuable antibacterial compounds for use in mammals including man. This disclosure relates to such compounds and a process for the preparation thereof.
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- Novel penicillins and cephalosporins and process for producing the same
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Novel penicillins and cephalosporins and non-toxic salts thereof, which contain a mono- or di-oxo- or thioxo-piperazino(thio)carbonylamino group have been prepared. These compounds are valuable antibacterial compounds for use in mammals including man. A process for the preparation of the compounds has also been discovered.
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