Synthesis Of Novel 14 Substituted 12

In the next step, 2-((5-amino-1,3,4-thiadiazol-2-yl)thio)-N-(4-fluorophenyl)acetamide (3a) was subjected to condensation reaction to afford N-(substituted)-2-((6-oxo-5,6-dihydroimidazo[2,1-b][1,3,4]thiadiazol-2-yl)thio)acetamide (4a-m) and their structures were confirmed by spectral analysis. The FT-IR spectrum of compound (4a) showed characteristic absorption bands at 3255cm-1 (NH), 3024cm-1 (ArC-H), 1614 (C=O), 1263cm-1 (C-S) and 1588cm-1, which could be attributed to (C=N). The 400MHz 1H-NMR spectrum of compound (4c), showed a singlet for the amide NH proton at δ 10.37ppm. The signal corresponding to the two protons of NH2 group in the 2-aminothiadiazole ring disappeared and a new sharp singlet for imidazole protons was appeared

Thus, adopting the same synthetic strategy for teneligliptin as described for PF-734200 by Pfizerref, optimization studies were carried out to improve the reaction condition and overall yield. The major key difference between PF-734200 and teneligliptin was in piperazinyl moiety, in PF-734200, piperazine is linked with pyrimidine where as in teneligliptin it was connected to 3-methyl-1-phenylpyrazole moiety. To know whether this structural difference in nucleophile may impact its reactivity in SN2 conditions with different activated form of Boc-trans-4-hydroxy-L-proline methyl ester (12) such as mesylate (12a), p-toluenesulfonate (12b) and nosylate (12c), reaction of 4, was performed with 12a, 12b and 12c. The 1-(3-methyl-1-phenyl-1H-pyrazol-5-yl)piperazine 4 used in the process was synthesized in bulk as per reported procedeureref with modified work up required for scale up point of

Garner, C., George, C., & Primrose, P. (2017). CHE 3238 Organic Chemistry Laboratory Manual – Baylor University (Fall 2017, Spring and Summer 2018 ed.).

[27] Aluminium (III) isopropoxide is widely versatile catalyst giving different reactivity in different type of solvents. Aluminium (III) isopropoxide do not exist in single molecules but as trimers or tetramers that do not have the same reactivity. [7] As seen in figure 7, an equilibrium state can be achieved between trimers and tetramers with tetramers being more stable. The actual catalyst-initiator for ROP of e-caprolactone is prepared by dissolving the trimers in e-caprolactone which separates itself into single molecule to form a six-coordinated aluminium complex, figure 8. [28]

The condensation product of primary amines with active carbonyl compounds have resulted in the formation of Schiff base compound. This has been reported by Hugo Schiff in 1864. Schiff base compound contain azomethine -C≡N with a general formula RHC=N-R’ where R and R’ are alkyl, aryl, cyclo alkyl or heterocyclic groups which may be variously substituted. These compounds are also known as anils, imines or azomethines (Mishra N. et al, 2013). Structurally, a Schiff base is a nitrogen analogue of an aldehyde or ketone in which the carbonyl group (C=O) has been replaced by an imine or azomethine group (Figure 1.1) (Abu-Dief M.A et al, 2015).

Friedel-Crafts acylation of anisole with acetic anhydride was used in this experiement to synthesize 4-methoxyacetophenone with the use of a reflux apparatus. Friedel-Crafts reactions can be done by alkylation, which involves mixing an alkyl or acyl halide with a Lewis acid, or acylation, which is done with acid chlorides or anhydrides(Lefevre). Acylation was used because it does not have as many disadvantages aklyations reactions have such as polyalkylation, second electrophilic attacks, and the rearrangement of alkyl carbocation electrophile (McMurry). Acylation reactions require molar amounts of a Lewis catalyst, in our case Aluminum Chloride (AlCl 3) was used (Arata, Nakamura, & Shouji).

2-methylmercapto-4,5-dihydroimidazole hydroiodide was synthesized imidazolidine-2-thione by reaction with methyl iodide and this compound was used as the starting material. 2-alkylamino-imidazolines was obtained from the nucleophilic substitution reaction with 2-methylmercapto-4,5-dihydroimidazol hidroiyodür and different aliphatic amine such as, diamine, triamine and tetramine. The syntheses of the salts of these compounds were prepared from the reaction of the 2-alkylaminoimidazolines and various organic acids such as, succinic acid, picric acid, fumaric acid and phthalic

1,3,4-thiadiazine can make either by using the heterocycles including thiadiazole and oxathiol or by diels-alder reaction. In addition, synthesis of 1,3,4-thiadiazine

It is commonly accepted that a majority of the published work in organic chemistry involved at least one heterocyclic ring. Heterocycles can play a pivotal rile not only as goals in synthesis, but as mediators of synthetic transformations. Isoxazoles are unique in their chemical behavior not only among heterocyclic compounds in general but also among related azoles. This is because isoxazoles possess the typical properties of aromatic systems, which are in fact rather pronounced in these derivatives, together with high labiality of the ring under certain conditions, particularly route to liberate the latent functionality. From a purely formal point of view isoxazole can be considered an analog of pyridine just as furan is an analog of benzene. Such formal analogy is to some extent valid; for isoxazole resembles pyridine more than other heterocyclic compounds as far as chemical properties are concerned. It differs from pyridine in undergoing more readily electrophilic substitutions reactions and possessing a more labile ring this relationship thus resembles that between furan and benzene.

A convergent and synthetically flexible routes to unsymmetrical calixarenes is developed, by integrating the unsymmetrical slices together to form unsymmetrical calix[n]arenes. For example, synthesizing calix[4]arenes by using 3 + 1 strategy and the 2 + 2 strategy (Figure 2), by combining a monomer and a trimer or two dimers together to form unsymmetrical calix[4]arenes. These processes are inevitably longer but are often a method of choices for the construction of calixarenes designed for specific applications (Gopalsamuthiram, V., & Wulff, W. D. ,2004) . The 3 + 1 strategy is condensing a p-alkylphenols with a linear trimer to produce unsymmetrical calix[4]arenes (Figure I). The shorter route (Route A) involves a symmetrical linear trimer (R1, R2, R1) prepared by treating a methylphenol with excessive phenols. If an unsymmetrical linear trimer (R1, R2, R3) is desired, the longer route (Route-B) must be applied, this route involve protection and deprotection procedures, it is more complicated to produce. Nonetheless, the complementary approach, the 2+2 strategy is condensation of two different diphenylmethanes to yield a unsymmetrical calix[4]arenes (Figure R) (Gutsche, C. D. ,2008). These two methods can create a calixarene with different

Optically active 1,3-diols are very important compounds in asymmetric synthesis, since they represent chiral building blocks for many polyketide-derived natural products, and have frequently been used as valuable intermediates in the synthesis of drugs and natural products with important biological activity. Such diols have shown promise as chiral derivatising agents and less frequently as chiral ligands.

In the view of the aforementioned remarked values of inhibition efficiency of this class of organic inhibitors, this paper aims to study the concerned function of the first utilized Schiff bases 3a-k towards mild steel in 0.5 M H2SO4 solution. N-aryl- (Sb_a-g), N-heteryl- (Sb_h-j)-, and the Schiff base Sb_k have been obtained condensation of N-aminophthalimide (S) with the corresponding aromatic aldehydes 2a-e, heterylaldehydes 2f-j and isatine 2k, respectively. This study takes into account the beneficial role that could be played by the p-electrons of the heterocyclic aldehyde or ketone N- and O- atoms present in the heterocyclic aldehyde and ketone moieties. The name of products and symbols were listed in Table 2. The melting point, yield, time of reaction and IR spectra of products were listed in Table 3. Spectral study has been used to characterize the structure of the novel synthesized Schiff bases (Sb_f-k) which to our knowledge have not been previously reported as shown in Table 4. The structure of the Schiff bases Sb_a-e was confirmed by identity of melting point and spectral data in the literature 25-27. The infrared spectra all the products Sb_a-k revealed that no coupling bonds in the 3 Mm region that refers to the absence of the amino –NH2 functionality of compound S instead a sharp absorption band appears on the region of 1604-1688 cm-1. Characteristic to the imino –c=N- group, indicating that compound

The validated 3D QSAR pharmacophore model Hypo1 was used as a 3D structural query for retrieving potent compounds from NCI database and Maybridge database having 238819 molecules and 2000 molecules respectively .A total of 8833 compounds were showing good mapping with Hypo1 using fast and flexible search method. Out of 8833 compounds 8530 compounds were from NCI and 333 compounds were from Maybridge database. Out of these 8833 molecules, selected only 2033 molecules were selected having their IC50<1 µM for study. These hit compounds were further screened by using Lipinski’s rule of five, to evaluate them drug similarity, and a total of 1613 molecules passed this evaluative process. These 1613 molecules were further subsequent for

Many naturally occurring medicines containing heterocyclic moieties in their basic structure such as antibiotics like cephalosporin (4), penicillin (5), morphine (6) as analgesic, alkaloids like caffeine (7), nicotine (8) and quinine (9) as anti-malarial drug. On the other hand, novel heterocyclic compounds have been synthesized by synthetic chemist due to their excellent pharmacological activities. These heterocyclic molecules are biological active as antifungal [11], antidepressant [12-13] anticonvulsant [14-15], anti-inflammatory [16], antibacterial [17], antitumor [18] and more (Figure-2).

SYNTHESIS, SPECTRAL AND BIOLOGICAL ACTIVITIES OF PYRIDINE 2,6 DICARBOXALIC ACID HYDRAZONE DERIVATIVES AND ITS METAL COMPLEXES