- CONFORMATIONAL EQUILIBRIUM AND VIBRATIONAL SPECTRA OF 2-ISOCYANO ETHYLCYANIDE
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The infrared spectra of 2-isocyano ethylcyanide as a liquid, a polycrystalline solid and in apolar solvents have been measured.Raman spectra were recorded for the liquid.The data were interpreted in terms of an equilibrium between trans and gauche rotamers.In the liquid, both conformers are present, while in the solid only the gauche conformer was found.Apolar solvents favour the trans rotamer.A complete vibrational assignment has been proposed for both conformers and discussed with respect to the assigned spectra of related molecules.
- Schrumpf, G.,Martin, S.
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- Gd-TEMDO: Design, Synthesis, and MRI Application
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A simple Ugi tetrazole multicomponent reaction allows the synthesis of a novel macrocyclic cyclen derivative with four appendant tetrazole arms in just two steps in excellent yields. This ligand, called TEMDO, turns out to have a high complexation affinity with lanthanoid metals. Here we describe the design, synthesis, solid-state structure, binding constant, and some MRI applications of the Gd-TEMDO complex as the first example of a congeneric family of oligo-amino tetrazoles.
- Boltjes, André,Shrinidhi, Annadka,Van De Kolk, Kees,Herdtweck, Eberhardt,D?mling, Alexander
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- Synthesis method of formyl pyrimidine
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The invention discloses a synthesis method of formyl pyrimidine, which comprises the following steps: (1) by using formamide and acrylonitrile as raw materials, carrying out Michael addition reactionunder the action of a catalyst A and post-treatment to obtain 3-formamide propionitrile; (2) by taking 3-formamido propionitrile and paraformaldehyde as raw materials, carrying out condensation reaction in the presence of a catalyst B and a benzene solvent, and carrying out post-treatment to obtain N-(2-cyanovinyl)-formamide; and (3) with N-(2-cyanovinyl)-formamide and free acetamidine as raw materials, carrying out a condensation reaction in a low-grade fatty alcohol solvent, then heating, carrying out oxidative aromatization under the action of a catalyst C, and finally, carrying out post-treatment to obtain formyl pyrimidine. The synthesis method disclosed by the invention has the advantages that the route is green, safe and environment-friendly; and an activating group and a leaving group are not adopted, so that the atom economy of the reaction is high.
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Paragraph 0078-0091
(2020/07/03)
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- Cleavable β-Cyanoethyl Isocyanide in the Ugi Tetrazole Reaction
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β-Cyanoethyl isocyanide is introduced as a cleavable isocyanide in the Ugi tetrazole reaction. Eleven examples are described that exhibit a broad scope and are obtained in good overall yields. The obtained 1H-tetrazole scaffold is an important bioisostere for carboxylic acids, and the method described here is a valuable alternative route to known procedures.
- Kroon, Edwin,Kurpiewska, Katarzyna,Kalinowska-T?u?cik, Justyna,D?mling, Alexander
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supporting information
p. 4762 - 4765
(2016/10/14)
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- One-step ring preparation of 2-methyl-4-amino-5-amino methyl pyrimidine convenient synthetic method
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The invention relates to a portable synthesis method for preparing 2-methyl-4-amino-5-aminoethylpyrimidine through one-step cyclization reaction. The method comprises the following steps: directly catalyzing acetamidine hydrochloride and 3-acyl aminopropionitrile to condense and to react with triester orthoformate for dealcoholization and cyclization by using lewis acid, and then hydrolyzing to obtain a vitamin B1 key intermediate, namely the 2-methyl-4-amino-5-aminoethylpyrimidine. According to the method disclosed by the invention, the raw materials are low in cost and easily obtained, and no sodium alcoholate needs to be used for dissociating acetamidine hydrochloride, thus the decomposition of acetamidine is reduced, and the high yield is achieved through reaction; the cyclization and hydrolysis reactions are sequentially carried out, products in all steps are not required to be separated and purified, and the synthesis method is simple and convenient to operate. Highly carcinogenic o-chloroaniline or other micromolecular aniline compounds are not used, and the portable synthesis method is environment-friendly in process, free of production of wastewater and beneficial to industrial production.
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Paragraph 0038-0040
(2017/03/08)
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