Triazolo [1,5 - a ] triazin-7-one衍生物和高度官能化的[1,2,4]三唑的合成
摘要:
介绍了新型三唑并[1,5- a ]三嗪-7-ones的合成。从3-氨基-5-硫烷基-1,2,4-三唑开始,合成序列包括用苄基溴进行烷基化,与氯甲酸对硝基苯酯反应,然后用伯胺处理,并与二乙氧基甲基乙酸酯缩合。用3-氯过苯甲酸最终氧化硫醚部分,得到总体良好的2-(苄基磺酰基)[1,2,4]三唑[1,5- a ] [1,3,5]三嗪-7- a 5a和5b产量。5a和5b的治疗与仲胺的混合物通过意外的三嗪酮开环提供了高度官能化的[1,2,4]三唑。提出了这种转变的机制。
Schmidt Reaction of ω-Azido Valeryl Chlorides Followed by Intermolecular Trapping of the Rearrangement Ions: Synthesis of Assoanine and Related Pyrrolophenanthridine Alkaloids
作者:Shao-Lei Ding、Yang Ji、Yan Su、Rui Li、Peiming Gu
DOI:10.1021/acs.joc.8b03018
日期:2019.2.15
The Schmidt reaction of ω-azido valeryl chlorides in the presence of an additional nucleophile was explored. The arenes, alcohols, and amines were demonstrated as the intermolecular trapping reagents for isocyanate ion and N-acyliminium ion from the Schmidt rearrangement, affording the corresponding products with moderate to excellent yields. Two 2-oxoindoles from the reaction were successfully converted
Ureaderivatives are obtained in mild to good yield from the reactions of primary aliphatic amines with CO2 in the absence of any catalysts, organic solvents or other additives. To optimize reaction conditions, experimental variables including temperature, pressure, the concentration of amine, reaction time etc. were studied. Satisfactory yields were obtained at the optimized conditions that are comparable
Process for the N-alkylation of ureas by reacting a urea with an alkylating agent in the presence of a solid base and a phase transfer catalyst in a diluent.
Selective hydrolysis of carbonimidodithioates (3) leads to the thiocarbamates (4), which can be easily transformed to the unsymmetricalureas (5) by treatment with the appropriate amines. This constitutes a synthesis of ureas without the use of phosgene or carbonmonoxide.
The synthesis of N-substituted ureas I: The N-alkylation of ureas
作者:Kurt A. Hackl、Heinz Falk
DOI:10.1007/bf00816855
日期:——
Urea and N-alkylureas are N'-alkylated in low yields using aprotic dipolar solvents, like dimethylsulfoxide, solid potassium hydroxide, and alkyl halides. Phase transfer catalysis with tetrabutylammonium chloride in refluxing toluene results in high yield regioselective N'-alkylation of N-alkylureas by means of alkyl halides, tosylates, mesylates, and sulfates as alkylating agents and alkali hydroxide as the base - however, N-arylureas are not alkylated under these conditions. Kinetic studies point to a S(N)2 type reaction which obeys the Kornblum rule.