16519-53-2Relevant academic research and scientific papers
One-Pot Four-Component Assembling for Selenoureas
Li, Lai,Wu, Jiaqi,Wei, Linsha,Lu, Jianmei,Jiang, Xuefeng
, p. 446 - 454 (2020/12/23)
An efficient and practical method for the straightforward construction of unsymmetrical selenoureas and cycloselenoureas via the combination of selenium powder, chloroform, and two different amines was comprehensively achieved in one-pot with only the assistance of a base under mild conditions. Thirty-three new structures of unsymmetrical selenoureas including three chiral examples and eight cycloselenoureas were achieved. 1,1-Dimethyl-3-phenylselenourea II, which shows good fungicidal activity, was practically synthesized through this protocol in gram-scale. Isoselenocyanate was further confirmed as a key intermediate by control experiment.
Tunable NIR-II emitting silver chalcogenide quantum dots using thio/selenourea precursors: Preparation of an MRI/NIR-II multimodal imaging agent
Basel, Siddhant,Bhardwaj, Karishma,Borthakur, Sukanya,Brito, Beatriz,Clarke, Mitchell,Pariyar, Anand,Pradhan, Sajan,Roy, Pankaj,Saikia, Lakshi,Shankar, Amit,Stasiuk, Graeme J.,Tamang, Sudarsan,Thapa, Surakcha
supporting information, p. 15425 - 15432 (2020/11/18)
Aqueous-stable, Cd- and Pb-free colloidal quantum dots with fluorescence properties in the second near-infrared region (NIR-II, 1000-1400) are highly desirable for non-invasive deep-tissue optical imaging and biosensing. The low band-gap semiconductor, silver chalcogenide, offers a non-toxic and stable alternative to existing Pd, As, Hg and Cd-based NIR-II colloidal quantum dots (QDs). We report facile access to NIR-II emission windows with Ag2X (X = S, Se) QDs using easy-to-prepare thio/selenourea precursors and their analogues. The aqueous phase transfer of these QDs with a high conservation of fluorescence quantum yield (retention up to ～90%) and colloidal stability is demonstrated. A bimodal NIR-II/MRI contrast agent with a tunable fluorescence and high T1 relaxivity of 408 mM-1 s-1 per QD (size ～ 2.2 nm) and 990 mM-1 s-1 per QD (size ～ 4.2 nm) has been prepared by grafting 50 and 120 monoaqua Gd(iii) complexes respectively to two differently sized Ag2S QDs. The size of the nanocrystals is crucial for tuning the Gd payload and the relaxivity.
Synthesis method of selenourea derivative
-
Paragraph 0097-0114, (2020/04/22)
The invention discloses a synthesis method of a selenourea derivative, and the method comprises the following steps: mixing 1-5 parts by mole of a first amine, 5-12 parts by mole of chloroform, 2-8 parts by mole of an alkaline substance and a reaction solvent under the protection of nitrogen or argon, and reacting for 1-6 hours while stirring at 25-80 DEG C; adding 1-6 parts of selenium powder, 1-4 parts of an alkaline substance, 1 part of morpholine or 1 part of a second amine, carrying out a stirring reaction at 25-80 DEG C for 3-8h to obtain a reaction solution, and carrying out post-treatment on the reaction solution to obtain the selenourea derivative, the synthesis method of the selenourea derivative disclosed by the invention has the beneficial effects that (1) the raw materials aresimple and easy to obtain, and the reaction conditions are mild; (2) the product yield is relatively ideal; and (3) the synthesis of the asymmetric selenourea derivative can be realized.
Synthesis of 4-(phenylamino)quinazoline-2(1H)-selones and diselenides from isoselenocyanates: Dimroth rearrangement of an intermediate
Atanassov, Plamen K.,Linden, Anthony,Heimgartner, Heinz
, p. 1873 - 1887 (2007/10/03)
The reaction of anthranilonitriles 8 with phenyl isoselenocyanates (1a) in dry pyridine under reflux gave 4-(phenylamino)quinazoline-2(1H)-selones 9 (Scheme 2). They are easily oxidized and converted to diselenides of type 11. The analogous reaction of 8a
