Organic Chemistry

I like to check one of my fraction which was eluted with 100% hexane from column and the content is high and showing single spot on normal phase TLC. The spot lies on the solvent front as the mobile phase solvent chosen is 100% hexane. So it could be mixture of hydrocarbons. I would like to know how many compounds this mixture does contain. If reverse phase TLC would be an option what is the best mobile phase solvent system to achieve good resolution? Help would be much appreciated.

Hi there! As long as I can remember, an addition reaction consists of both an electrophile and nucleophile. Everytime, the nucleophile is "the one attacking" and the electrophile is "the one attacked". If nucleophilic addition reaction is named in such a way that the reaction is initiated by a nucleophile (it attacks), then electrophilic addition reaction must be occurring in such a way that the electrophile is the one that initiates the reaction. My question is, how does an electrophile initiate an addition reaction when it's always "attacked"? Thank you.

how do u predict whether halogenation will occur in the side chain or aromatic nucleus in arenes depending on reaction conditions

Hello to all: Where can I find a list of all Carboxylic acids and Hexose acids? Is there an easy way to tell them apart? Can a substrate be both? Can a Carboxylic acid also be considered a Dicarboxylic acid? I need a good resource to find differences between, say, Gluconic and Glucuronic acids. Some internet resources say that Guconic acid is a Hexose acid while Glucuronic acid is a Carboxylic acid, others say they are both Hexose acids.. I am researching microbial metabolic substrates but need some fundamental background. Any help is greatly appreciated. Thank you! I see Hexose acids are derived from oxidized hexose sugars - i.e., sugars with six Carbon molecules. …

I'm looking for the mechanism for the reaction which converts a benyzlic carbon (with a hydrogen) into a carboxylic acid using MnO4-. Googling has yeilded several sites mentioning the reaction, but none explaining the mechanism and I'm not sure where to look. I was told the mechanism involves radicals, but I know nothing more than this. Can anyone help?

Hi all. I am not sure how I would derive this measurement for my lab. My ochem lab is asking for 'a twofold excess of thionyl chloride.' Not sure what this means. Physical constants I have for thionyl chloride are its MW= 119 g/mol and d= 1.64 g/mL. The other reagent I will put into an RBFalong with the thionyl chloride is 0.4g of m-toluic acid. Do I incorporate 0.4g into my calculation for the excess thionyl chloride? Thanks!

I'm beginning to prepare for an annual fourth of July firework show for a family get together. I have about 4 lbs of Potassium nitrate, and tons of sucrose at hand. I looked online and powdered dye is quite expensive ($65+), so I was wondering...would adding ground colored chalk to the KNO3 + sugar mixture cause the smoke to be colored? -cheers

Hi I want to synthesize Benzalacetone I tried the following procedure but the product obtained was dibenzalacetone. Combined 1.9ml of benaldehyde, 0.8ml of acetone, 6ml of 5M NaOH 15ml of ethanol and stirred for 30 min. Washed the resulting crystals with distilled water, recrystallized in in ethanol, filtered and washed crystals with cold solution of ethanol/water (70:30). The mp was 98C.

Recently took a NMR spectrum, of my natural product sample and it showed intense -CH2 peak at 1.2 ppm in the H NMR spectrum. But the integration value mentioned is 69. Is it an error? If so how can i overcome this? Appreciate your suggestions. Note that C13 showed only 13 peaks

Hello! I'm going to be following a procedure for a reflux reaction and I'm a bit confused on the directions after refluxing for 8 hours. My desired product after refluxing will be a liquid. I'm confused about which "residue" that will be dissolved in ethyl acetate: the liquid product or the solid collected with the celite filter aid. Assuming that everything in bold was done to my liquid solvent collected from vacuum filtration, is it asking to do a second vacuum filtration to remove the drying agents? Also, what's the purpose of adding ethyl acetate to my solution? My theoretical yield should be 1.76 mL of pure Allyl Phenyl Ether. It seems odd to add such a larg…

I have synthesized a glycol modified silane from the starting materials of 1,2-propane diol and methyl trimethoxysilane. The structure of the product can be found below. The process involves removal of methanol by distillation under an inert atmosphere at a high temperature (140 degrees C for 16 hours). My question involves the following. My product smells like old gym socks marinated in rubbing alcohol then left to ferment under a leaking sink for a year. I have made dozens of variations on this compound and none of them smell like this. The 1H and 13C NMR on this compound look clean. Can anyone suggest why my compound smells so terrible? My current theorys i…

I have to synthesize 4-Iodo-3-nitrobenzamide using a starting product that contains no more than 8 carbons. The materials have to be purchased so they must be reasonable in price as well. I was thinking about starting with Iodobenzene since it is an Ortho/Para director. After that I was thinking about adding the amide group but I am unsure of how I want to do the addition. A nitro addition would come after and that should add in the correct place because both substituents would direct it appropriately. Any suggestions on how to prepare the amide and then actually react it with the iodobenzene? Thanks in advance

Hey everyone i have a question, I have an oil obtained by soxhlet extraction using ethanol. What would i do to obtain crystals out of this oil. Keep in mind the crystals will be intended for consumption so i cannot use any harsh ingredients.

Hello everybody, I'm currently trying to dissolve a carotenoid (Astaxanthin). I did it in ethanol, DMSO and Polyethylene glycol. But the problem is that these 3 solvents interfere with the subsequent analyses I'm trying to do. Does anybody have an idea what other solvent I could test? It should be miscible in water and not have toxic effects on cells and membranes. Thanks in advance for any suggestion Have a nice weekend

I have a mixture of an aromatic diketone and its anhydride. I was not able to separate them with column chromatography as they came out almost at the same time and the process was so time consuming in the case of using longer column. I also have to work with small amount of materials and most of my product was wasted in column.. I was wondering if anybody knows a better separation method?

hello, if you have the compound : 2,6,6-trimethyl-4-(1-methylethyl)nonane the trimethyl and the branched 1-methyl- both starts with the letter "m", how do you choose which one gets the priority? according to the numbers (2 or 4)?

First off I don't want to break any laws (UK or international) or at least I don't intend to:-) I was wondering if anyone knows how a private individual such as myself (I'm legaly an adult) could obtain small quantities of petroleum ether. Ebay is a dead loss as is amazon and everywhere else only sells to registered companies and in massive quanities 25gallon.

So bond energy is the same bond enthalpy, which means the amount of energy needed to break the bond. Based on this definition, you would need to put in more energy to break the bonds of cyclohexane than cyclopropane due to the increased stability of cyclohexane, correct? From a combustion rxn, which would yield more energy: cyclopropane or cyclohexane? I would think cyclopropane due to the high ring strain within the molecule.

Hi, I'm currently dealing with amine synthesis and since I'm new on this field I also don't have much experience on the purification. Here's my problem: I tried an unusual method to convert a benzylic nitrile to the corresponding amine. It involves DIBAL-H, NH4Br and NaCNBH3. I can't use LiAlH4 or H2 to reduce the nitrile as it would mess up other functionalities in the molecule. After acid base extraction the TLC (silica, EE/MeOH, 10:1, 5% TEA) of the crude product showed several spots whereas only one of them was blue/purple (ninhydrin). The other ones were somewhat brown or yellow... After column chromatography (same system as above) I was able to isolate all spo…

Hello, all. I am attempting to read about Focalin XR: d-threo-methylphenidate - wikilink: http://en.wikipedia.org/wiki/Dexmethylphenidate I have a few questions: 1. Is it an amphetamine? 2. Is it like an amphetamine? 3. If it is like an amphetamine, then can it give a person delusions of persecution like an amphetamine? I know the third question goes into the realm of psychiatry, but those three questions are of my primary interest at the moment.

I am trying to find the theoretical yield and percent yield in nitrotoluene. The question: Exactly 4.0 mL of toluene (density = 0.87 g/mL) were reacted with excess nitric acid in the presence of excess sulfuric acid, and 3.6 g of nitrotoluene were obtained. So I started with the balanced equation: C7H8 + HNO3 --> C7H7NO2 + H2O Then I calculated the grams of toluene: 4.0mL * 0.87g/mL = 3.48g C7H8 Then I calculated the moles of toluene: 3.48g * 1 mole/92.138g = 0.038 mole C7H8 Then I calculated the moles of nitrotoluene: 3.6g * 1 mole/137.136g = 0.026 mole C7H7NO2 This equation is a 1:1 ratio so I can't multiply by anything, so tryin…

The heats of combustion (to CO2 and H2O) of some C5 compounds are given below. Z-2-pentene –3369 kJ/mol E-2-pentene –3365 kJ/mol 1-pentene –3376 kJ/mol pentane–3536 kJ/mol The heat of formation of CO2 is –393 kJ/mol and that of H2O is –285 kJ/mol. What is the heat of hydrogenation of 1-pentene (in kJ/mol)? There are three questions on my OCHEM practice exam like this, and I can't understand any of them. I understand everything else, but I want the extra 50 points. I know how to calculate delta h using BDE, but that's where my knowledge stops.

Hello great minds, we have a clinical lab, that screens urine samples for substance abuse . We have decided to perform GCMS in house, rather than send out. We need help/ consultation 1. which co/ model of GCMS equipment is the best to buy? What are pros and contras for different manufactures ? 2. Where and how can we train a technologist to work on it? 3 does anyone have the right people to work on this equipment or help to choose the right machine and get it up and running? 4. Location of facility NyC and NJ, if you know qualified staff, we are looking to hire or to get training

Hello, I try to make formate silver (AgCHOO) to enhance my silver halide holographic plates. I have make silver carbonate and have formic acid. My question is : Can I mix formic acid with acetone without degradation of acid ? Seems formic acid + acetone form esters but is it degrade the potential of this acid ? The reaction between formic acid and silver carbonate must be done at low temperature, preferably below 0*C this why I think of acetone to get low temperature. Thanks in advance.

NMR HELP C13H180 On my NMR there were 3 Aromatic Hydrogens A singlet A septet and doublet (isopropyl group) quartet and triplet (ethyl group) Would it make sense to have three substituents? NMR HELP C13H180 … — OpenStudy.html