Pentiptycene Quinone Synthesis

The purpose of the experiment is to determine the chemoselectivity of different reducing agent or reductant by reducing 3-nitroacetophenone with tin and hydrochloric acid. For this research, 3.45g of tin granular was put into a 100mL of round bottomed conical flask attached to a reflux condenser; then add 1.6585g of 3-nitroacetophenone and 24mL of water. Heat the mixture over oil bath for 90 minutes. At the end of the process, 0.4115 grams of final product were obtained giving a percent yield of 30%. Analyzing tests including melting point determination, IR Spectroscopy and TLC were done on the final product to analyze the properties of the product. The melting point was found out to be 98.2ᴼC. TLC using solvent system 60% ethyl acetate and

Mayo, D. W.; Pike, R. M.; Forbes, D. C. Microscale Organic Laboratory with Multistep and Multiscale Syntheses, 5th ed.; John Wiley & Sons, Inc., 2011; pp 132-135.

The goal of this was to successfully accomplish the synthesis of para-Chlorophenoxyacetic acid. In this experiment, para-Chlorophenoxyacetic acid was synthesized from 4-chlorophenolate and chloroacetic acid using an SN2 reaction. The product obtained was determined to be the para isomer of Chlorophenoxyacetic acid. This was confirmed by the melting point of 157.3-157.9 ◦C. The percent yield determined at the end of the experiment was 37.83 %. The TLC analysis showed that P-Chlorophenol was less polar than P-Chlorophenoxyacetic Acid because it had an Rf value of 0.38 in comparison to the value of 0.33 on a 50:50 hexane and ethyl acetate solvent mixture. In the NMR comparison, it was shown that both the starting material of chloroacetic acid and product contained a peak of integration two around 4 ppm representing the acidic proton. In the FT-IR comparison, it was determined that the Chloroacetic acid and the para-Chlorophenoxyacetic acid both had an OH bond at 3416 cm-1 and 3429.72 cm-1 respectively. The Chloroacetic acid and para-Chlorophenoxyacetic acid also both had a carbon-oxygen double bond at 1648 cm-1 and 1654.81 cm-1 respectively. The para-Chlorophenoxyacetic acid also contained a peak at 1236.18 cm-1 which represents the C-O-C bond.

To a solution of substituted chloro quinoxaline compound (2a) (4.5g, 12.9 mmol) weighed into a round bottom flask was charged with PdCl2 (dppf).DCM (6%mol, 0.633g). A toluene: ethanol mixture in 2:1 ratio (40 ml+20 mL) was degassed with nitrogen gas, and then added into the flask. Aqueous 1 molar sodium bicarbonate solution (24 mL, 19.30 mmol) was degassed and added to the mixture. The mixture was stirred at room temprature for 15 minutes under nitrogen. The 3-methyl phenyl boronic acid (2.1 g, 15.48 mmol) or respective boronic acid (2-methoxy phenyl boronic acid/ 3-methoxy phenyl boronic acid/ 2-fluoro boronic acid) was added as the solid.

Trans-stilbene (1,2-diphenylethene) was synthesized in a two-step reaction. Trans-stilbene was brominated to give meso-stilbene dibromide in the first reaction. The stilbene dibromide was heated with base in order to induce dehydrobromination. One of the methods used throughout this experiment was vacuum filtration. An 81% yield was obtained due to a few minor errors. The compound seemed to be pure due to the relatively close melting point ranges.

In this experiment, sodium borohydride will be used to reduce 4-tert-butylcylohexanone into two 4-tert-butycycohexanol diastereoisomers with differing stereochemistry. Sodium borohydride is preferred over lithium aluminum hydride as a reducing reagent due to its “weak reducing agent” property. Using sodium borohydride allows for a more selective reduction around other functional groups, such as if you had a molecule that contains a carboxylic group and acetone, sodium borohydride will only reduce the ketone since it doesn’t have the capability of reducing the acid. The 4-ter-butylcyclohexanol diastereoisomers products were isolated by a liquid-liquid extraction involving dichloromethane in order to separate the organic and aqueous layer.

=O and C =C aromatic stretches (Table 1) that correspond to the literature value6, but are less intense explained by the low yield. To improve the yields of this multistep synthesis the procedure should be modified to allow a longer reaction time to condense all of the benzaldehyde to benzoin in the first step as 1.5 h is not sufficient as shown by the TLC. Furthermore, recrystallization should be performed after each synthetic step as to remove impurities and potential side products that may

Quinolines are remarkable scaffold found in several biological and pharmaceutical agents.1 Many tetrahydroquinoline moieties are known to be an interesting therapeutic agents.2 For example, the tetrahydroquinoline-based natural product (Fig.1) isolated from Galipea officinalis have been reported as potent antimalarial

The progress of the reaction was monitored by TLC. After completion, the reaction mixture was cooled to room temperature and the crude product was obtained. The product was then isolated via column chromatography on a silica gel using ethyl acetate/dichloromethane (1:1, Rf = 0.32) as the eluent to obtain a yellow solid N-allyl-4-iminodi(N-benzylacetamide)-1,8-naphthalimide. Yield: 46.7 %, M.p.: 204–206 °C. 1H-NMR (DMSO-d6, 300 MHz): δ= 8.496-8.439 (m, 2H, ArNaphthyl-H); 8.466 (s, 2H, NH ); 8.319-8.291 (m, 1H, J = 8.4Hz, ArNaphthyl-H); 7.693-7.640 (m, 1H, J = 8.4Hz, J = 7.5Hz, ArNaphthyl-H); 7.360-7.128(m, 10H, Ph-H); 7.000-6.947(d, 1H, J =

synthesis of a wide range of alkenes, styrenes, stilbenes, and 1,3-dienes which can then be used

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).

Pyrrolo[1,2-a]quinoline (Fig 5.2) and synthesis of its derivatives were reviewed in 2003 by El-Sayed and El-Sayed 5. In literature, new methods or the

A 1,3,4-thiadiazole library was constructed by solid-phase organic synthesis. The key step of this solid-phase synthesis involves the preparation of polymer-bound 2-amido-5-amino-1,3,4-thiadiazole resin by the cyclization of thiosemicarbazide resin using p-TsCl as the desulfurative agent, followed by the functionalization of resin by alkylation, acylation, alkylation/acylation, and Suzuki coupling reaction. Both the alkylation and acylation reactions chemoselectively occurred at the 2-amide position of 2-amido-5-amino-1,3,4-thiadiazole resin and the 5-amine position of 2-amido-5-amino-1,3,4-thiadiazole resin, respectively. Finally, these functionalized 1,3,4-thiadiazole resins were treated with trifluoroacetic acid in dichloromethane,

All the chemicals used in the synthesis were of analytical grade purity and were purchased from Sigma-Aldrich (India). Rivastigmine was obtained as a gift sample from Sun Pharmaceutical Industries Ltd (Silvassa, India). Melting point of the synthesized analogues was determined by using Stuart melting point apparatus and were uncorrected. Equimolar (0.01mol) quantity of NaCNO in 25ml of warm water was added with continuous stirring, the reaction mixture was allowed to stand for 4 h and the product was obtained by filtration, washed with water, dried in an oven below melting point and recrystallized from ethanol to afford key intermediate-1 .The precipitate was obtained by filtration, washed with water, dried in an oven below melting point and recrystallized from ethanol to afford key intermediate-2 .Equal moles of intermediate-2 (0.456g, 0.003mol) in 5ml of ethanol mixed with equal moles of the different aldehyde or ketone was refluxed for 2hrs and glacial acetic acid was added to adjust the pH of the reaction between 5-6. The solid obtained after cooling was filtred, dried and crystallized from 95% ethanol to afford compounds .Ellman’s spectrophotometric analysis [16] was used to determine IC50 values. This method is based on the reaction between synthetic substrate acetylthiocholine iodide (ATChI) and 5,5-dithio-bis-(2-nitrobenzoicacid) (DTNB) to produce a yellow colour (5-mercapto-2-nitrobenzoicacid) which was detected by Colorimeter. Determination of IC50 values was performed by recording the rate of increase in the absorbance at 412 nm for 5 min.

Technically, water is considered as the universal solvent in Nature. However, the prevalent notion among today’s chemists is that water is often forgotten in organic synthesis; many considerations are taken in the process of selecting solvents, reagents, and conditions which are water-free. In addition to the obvious problem that concerns about the surrounding water-sensitive reactants, the main problem is solubility which is the requirement for reactions to occur, and it is a justification for the use of many organic solvents at the exclusion of anything else in organic synthesis. Nevertheless, many living biochemical reactions mostly happen in an aqueous medium. The concern about environment and safety is another reason that has flamed up the interest in Green Chemistry, which prompted more researches into alternatives to traditional organic solvents. Therefore, water is a very promising candidate for the future choice of solvent as it is cheap, reusable, nonvolatile and safe to handling of exothermic or heat-releasing reactions. Even though water has many advantages in organic synthesis, the low solubility of organics reagents has prevented the expanding utilization of water as a standard solvent.