762-42-5Relevant articles and documents
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Ykman,P.,Hall,H.K.
, p. 2429 - 2432 (1975)
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Sasaki,T. et al.
, p. 4413 - 4414 (1975)
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Synthesis of dimethyl acetylenedicarboxylate
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Paragraph 0013-0014; 0016; 0020; 0024, (2018/10/11)
The invention discloses synthesis of dimethyl acetylenedicarboxylate. The synthesis steps comprise: (1) dissolving 2,3-dibromosuccinic acid in methanol, adding concentrated sulfuric acid to the reaction solution in a dropwise manner, continuously stirring, and carrying out a reaction for 2-3 h to obtain 2,3-methyl dibromosuccinate; and (2) dissolving the 2,3-methyl dibromosuccinate obtained in thestep (1) into ethanol, adding an alkali substance, stirring, carrying out a heating reflux reaction, and carrying out post-treatment to obtain dimethyl acetylenedicarboxylate. According to the present invention, the operation is simple, the requirement on the operation technology of the technician is not high, the production cost can be effectively saved, and the dimethyl acetylenedicarboxylate obtained through the method has the high purity and can be directly used for the next reaction.
Mechanism and scope of the base-induced dehalogenation of (E)-diiodoalkenes
Resch, Daniel,Lee, Chang Heon,Tan, Siew Yoong,Luo, Liang,Goroff, Nancy S.
, p. 730 - 737 (2015/01/30)
A wide range of nucleophiles have induced the elimination of iodine from (E)-diiodoalkenes to form alkynes under surprisingly mild conditions. The iodide anion is particularly efficient, and can drive the reaction to completion in less than 1 hour at room temperature in a polar aprotic solvent. Detailed investigations have suggested the reaction has a bimolecular polar mechanism. The deiodination reaction can be driven to completion with 1 equiv. of nucleophile and is partially catalytic with substoichiometric amounts of deiodinating reagent. Kinetic analysis of the stoichiometric iodide-induced reaction indicated an overall pseudo-first-order behavior. The reaction exhibited strong solvent effects, with much slower reactions observed in protic solvents than in polar aprotic solvents. The substrate dimethyl (2E)-2,3-diiodo-butene-2-dioate demonstrated orthogonal reactivity for either elimination or hydrolysis, depending on the solvent and nucleophile used. This reaction is a major pathway for all the diiodoalkenes examined, and represents a challenge and an opportunity for using these substrates in organic synthesis.