3154-54-9Relevant articles and documents
Silver-Catalyzed Acyl Nitrene Transfer Reactions Involving Dioxazolones: Direct Assembly of N-Acylureas
Yang, Zheng-Lin,Xu, Xin-Liang,Chen, Xue-Rong,Mao, Zhi-Feng,Zhou, Yi-Feng
supporting information, p. 648 - 652 (2020/12/21)
Dioxazolones and isocyanides are useful synthetic building blocks, and have attracted significant attention from researchers. However, the silver-catalyzed nitrene transfer reaction of dioxazolones has not been investigated to date. Herein, a silver-catalyzed acyl nitrene transfer reaction involving dioxazolones, isocyanides, and water was realized in the presence of Ag2O to afford a series of N-acylureas in moderate to good yields.
Optimized synthesis process of anticancer drug dacarbazine
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Paragraph 0026; 0027, (2019/10/17)
The invention provides an optimized synthesis process of an anticancer drug dacarbazine. The optimized synthesis process of the anticancer drug dacarbazine comprises the following steps: synthesis ofglycine methyl ester, synthesis of N-formylglycine methyl ester, synthesis of alpha-methyl isocyanoacetate, synthesis of alpha-isocyanoacetamide, synthesis of 5-amino-4-imidazolecarboxamide and synthesis of dacarbazine. Synthesis of the glycine methyl ester comprises the following steps: weighing 7.5 g of glycine and adding the glycine into a 500 mL round-bottom flask, taking 200 mL of redistilledmethanol as a solvent and cooling with stirring in an ice bath for 15 min; weighing 22 mL of thionyl chloride by a syringe and slowly dropwise adding the thionyl chloride into the reaction flask to react overnight at room temperature; and removing excess thionyl chloride and methanol by rotary evaporation at the room temperature, dissolving the residues by using as little hot methanol as possible, quickly adding a large amount of cold diethyl ether, and cooling in the reaction bottle in an ice bath. By improving the synthesis process of the anticancer drug dacarbazine, the optimized synthesisprocess of the anticancer drug dacarbazine has the advantages of reasonable synthesis circuit, cheap raw materials, mild reaction conditions and high total yield, thereby effectively solving the problems and defects in the prior art.
4,5-Disubstituted N-Methylimidazoles as Versatile Building Blocks for Defined Side-Chain Introduction
Przybyla, Daniel,Nubbemeyer, Udo
supporting information, p. 695 - 703 (2017/02/05)
Fungerin is a 1,4,5-trisubstituted imidazole natural product characterised by a broad spectrum of antifungal activities. We planned to develop flexible strategies to access to such compounds. Imidazoles bearing suitable anchor groups at C-4 and C-5 allow the introduction of various substituted side-chains, generating libraries of fungerin derivatives for biological tests. Starting from commercially available reactants, two N-methyl 4,5-substituted imidazole core units were synthesised. Derivatives of type 1 contained two orthogonally protected C-1 anchors. Selective side-chain introduction was achieved through a sequence of Grignard coupling at C-5 to replace a tosylate and a Horner olefination through an aldehyde attached to C-4. Two target fungerin derivatives were synthesised. Since the organometallic substitution of the C-5-CH2-positioned leaving group proved to suffer from limitations concerning potential competing side-reactions, a type 2 imidazole core was built up. These structures had a halogen centre at C-4 and a hydroxyethyl anchor at C-5. Now, selective side-chain introduction allowed us to use Julia olefination to form the allyl side-chain at C-5 and Heck reactions to introduce the C-4 acryl substituents. Eight derivatives, including fungerin, were synthesised by this latter strategy, without producing any regioisomers. The second approach had the advantage that various side-chains could be coupled at C-4 and C-5 in two final steps. Thus, this strategy represents a versatile way to build up libraries of fungerin derivatives for biological testing.