- Method for preparing dimethyl-beta-propiothetin
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The invention relates to a method for preparing dimethyl-beta-propiothetin (DMPT), and relates to the technical field of organic chemistry. The invention adopts a two-step synthesis method comprising the following steps: firstly, preparing beta-dimethyl mercaptopropionic acid chloride from chloropropionic acid and dimethyl sulfide; and then adding sodium bicarbonate for reaction, and recrystallizing and drying to obtain the DMPT. The invention adopts a unique synthesis method, wherein a yield of an intermediate product synthesized in a first step is 65-84%, and the purity of the product DMPT after purification can reach 96%; and the method provided by the invention is high in purity of the product, simple in synthesis step and suitable for popularization and application.
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Paragraph 0012; 0014; 0016
(2017/12/27)
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- One-electron Reduction of Sulphonium Salts in Aqueous Solution: a Pulse Radiolysis Study
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Absolute rate constants have been measured for the reduction of 1-alkylthiolanium (1a-c), 1-alkylthianium (2a-e), 1-(n-carboxyalkyl)thiolanium (3a,b) and 1-(n-carboxyalkyl)thianium (4a,b) salts, and ω-dimethylsulphonioalkanoic acids (5a,b), including biologically active S-methylmethionine (6) and dimethyl-β-propiothetin (5b), by hydrated electrons in aqueous solutions using the pulse radiolysis method.This reaction was found to occur very rapidly (k in the range 109-1010 dm3mol-1s-1), the individual rate constants being dependent on the electron inductive power of the substituents on the positive sulphur centre.The sulphuranyl radical R3S., a possible reaction intermediate, could not be detected within the 0.1 μs time resolution of the applied technique.No reaction was observed between S-methylmethionine and CO2.- or Me2C.OH under experimental conditions.The one-electron reduction potential of this sulphonium salt has been estimated to be -aq. were characterized by using p-benzoquinone as a radical scavenger.It was found that ring opening is the predominant process rather than the cleavage of methyl or methyl radicals.
- Bonifacic, Marija,Anklam, Elke
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p. 243 - 248
(2007/10/02)
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