Solid-phase synthesis

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…

Synthesis of 10-Camphorsulfonamide (3) A three-neck flask, with a stir bar was charged with 18.4 mL of concentrated ammonium hydroxide. While on ice and with the stir bar mixing vigorously, 1.88g of 10-(camphorsulfonyl)chloride in 18.4 mL of methylene chloride was slowly over 20 minutes. This mixture was allowed to stir and react for 1.5 hours at 0° Celsius. The phases were then separated. The aqueous phase was washed with methylene chloride twice with 15 mL of methylene chloride. The organic…

the highest drug solubilization capacity for docetaxel. Whereas, Captex and Gelucire 44/14 shown the least solubility of docetaxel in them. Based on the solubility results, Capmul PG8 NF was selected as the oil phase, Cremophore EL as surfactant and Transcutol-P as co-surfactant. Capmul PG 8 NF (HLB 6) has partial aqueous solubility over Capmul MCM C8 which may help in easy dispersion of drug in an aqueous medium [34,35]. A good combination of surfactants with low and high hydrophilic lipophilic…

brainstorming activities. There were conflicting norms as the elders were not pleased that the younger group members were involved in drinking alcoholic beverages and because of the intoxication these group members contributed less than those who remained sober. Mimi explained that although the group represented the intended wheel network, the all-channel seemed more organic and are in the secondary tension phase. The next individual I conducted with the survey was a business man, named Mark.…

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…

This artifact is primary based on sample rates and to see the effects of sample rates by using Sinusoidal waves. Sinusoidal waves can be represented using frequency and period. The Frequency of a Sinusoidal wave is the number of complete cycles that happen in a particular period of time or in a given sample. The Period in terms of Sinusoidal waves, is the time it takes to perform one complete cycle. The Sinusoidal wave is a series of identical cycles happening repeatedly. The sample rate is the…

Tuckman has four phases of group development. The first being forming, the second being storming, the third being norming, and lastly the fourth being performing. Each of these four phases are influenced by different aspects of your group coming together and working. Essentially the three of these phases are meant to lead you to the fourth phase with success. My group has gone through all four of these phases throughout this semester, while working on our project for COM 240. Tuckman’s first…

and turbulent. Adolescents go through significant phases in their journey of figuring out who they are and how they fit into the fabric of everyday life. The first one being the naive phase; this is where we believe we know everything there is to know. This is the stagnant phase where we cannot see change and think about forever in the most literal sense. Second is the turbulent phase; where we find ourselves rebelling to anything that we feel is oppressive. Lastly is the phase of awakening, in…

Chapter eight of the text Sound and Recording by Francis Rumsey and Tim McCormick, discusses the principles of digital audio, and contrasts digital with analog. The text also illustrates how digital and analog work together to produce desired sound. In the world of audio there are two types; digital and analog. Analog can be described as physical or tangible in a sense, being etched onto some type of media. Digital however, is a representation of the audio waveform, which is converted into a…

In summary of the phases, a therapist will follow to administered therapeutic intervention with a client, termination is the last phase. The therapist should have built-in termination phase at the first phase of engaging and assessing the client. It will make it easier for both therapist and client to end well. It is the end of a worker-client relationship. But must be based upon convincing evidence that the goals and objectives have been achieved. Termination must end successfully. In Robert’s…