A novel solid-phase synthesis methodology of N-substituted-2-aminothiazolo[4,5-b]pyrazine derivatives was developed. The key step in this synthesis strategy is tandem reaction of isothiocyanate terminated resin 2 with o-halo-2-aminopyrazine, affording cyclized 2-aminothiazolo[4,5-b]pyrazine resin 4. To increase the diversity of our library, Suzuki coupling reaction was performed at the position C6. Further functionalization of 2-aminothiazolo[4,5-b]pyrazine core skeleton with various electrophiles such as alkyl halides, acyl chlorides, and sulfonyl chlorides and cleavage from the resin with TFA in DCM generated N-alkyl-, N-acyl-, and N-sulfonyl-2-aminothiazolo[4,5-b]pyrazine derivatives. This synthetic strategy can efficiently provide a library…
α-phenylcinnamoyl, naphthaloyl, 3-methoxy-4-phenoxybenzoyl, 9-fluorenylmethoxycarbonyl (FMOC), and tert-butylphenoxyacetyl (t-PAC) groups (Figure 2.1.7) provides greater resistance to depurination than with N6-benzoyl (reviewed in Beaucage and Iyer, 1992). It is believed that in the case of acyl-protected purine nucleosides under acidic conditions, the initial site of protonation is N7, rendering the protonated species more prone to glycosidic cleavage. Naturally, caution should be exercised in…
Green Synthesis of Ibuprofen Green Chemistry is a new approach and perspective of chemistry that can improve human lives and maximize efficiency. It is a branch in chemistry that explores and examines techniques to reduce and eliminate hazardous and harmful substances. These harmful substances effect humans and the environment in multiple ways, the twelve principles of Green Chemistry can help minimize them. The twelve principles include prevention of waste, the design of less hazardous…
1) Explain how the Lin et al. used the catFISH technique to determine which neurons are involved in particular behaviors (3 pts) Lin et al. used catFISH (cellular compartment analysis of temporal activity by fluorescent in situ hybridization) to compare the activation of c-fos expression during two successive episodes of behavior (either the same behavior or different) in the same animal. Through experimentation, researchers discovered that animals killed five minutes after fighting expressed…
Synthesis paper In my paper I wish to synthesize the works that we have covered in class by showing how they work together to show us the special elements found in every good story. All of the works that we have covered this year work together in many different ways. They also all share many elements of story such as conflict, themes, characters and development, setting, and plot. These elements differ in many ways such as themes being a very broad part of story and plot is a vast element. For…
The trope of nostalgic and wistful people looking back on their teen years, the good years, approaches stereotype. Julian Barnes’s The Sense of an Ending, on the surface, appears to employ the same stereotype of a wistful old man experiencing a bout of retrospection for his lost friend and the times he once had. The narrator of Carson McCullers’s “Ballad of the Sad Café” in The Ballad of the Sad Café works with the same forlorn recollection of when the town was more alive. Both narrators use two…
Bromination of trans-cinnamic acid Purpose and Introduction The halogenation of of trans-cinnamic acid using pyridinium tribromide was connected in the organic solvent glacial acetic acid in order to verify and test which addition mechanism the reaction would follow. In the anti-addition mechanism, bromines attach themselves on opposite sides of the alkene functional group in a compound. In a syn-addition, the attach to the same side of the alkene. The reaction synthesis was completed by using a…
devices. In addition, their novelty is rapidly growing in other fields where they are used as sensing elements in chemical sensors, electrocatalysts, liquid crystals, electrochromic display devices, information storage systems, semiconductors, functional polymers and molecular metals, among others. They have also found use in photodynamic therapy (PDT). [15-17] Synthesis of Phthalocyanines A number of different methods are available for the synthesis of phthalocyanines. Phthalonitriles are…
The goal of this experiment was to perform a synthesis of aspirin/ acetylsalicylic acid from salicylic acid, using a chemical synthesis procedure. The synthesis involved breaking the bond with acetic anhydride, also required heat and a catalyst, phosphoric acid, in order to beak and extract the bond. The solution used water in order to purify the solution in the way of recrystallization. The product was characterized using IR spectroscopy and melting point. The pure aspirin product that was…
Evolutionary biologists such as Richard Dawkins1 , Paul Meyers2, and Jerry Coyne3, and philosophers of science such as Daniel Dennett4, Micheal Ruse5, and Peter Singer6 have produced differing defences and explanations of Darwinism, its roots, and its various implications within a Neo-Darwinian framework. In many cases, these have been intended for wider consumption beyond academia and have incorporated the promotion of Darwin as a unique historical agent, with Dawkins arguably leading the pack…