N-4-phenyl picolinamide – Feb 10-Feb18 update

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TLC of KG04 together with reagents, phenylisocyanate, picolini acid, and diisopropylethylamine in ethylacetate/hexane eluent.

(Left, TLC in 1:9 ratio, center 2:3 ratio, right 2:3 ratio with components diluted)

The product KG04 was dissolved in acetone (not the one from the wash bottle), and TLC of of it was taken together with phenylisocyanate, picolini acid, and diisopropylethylamine in ethylacetate/hexane as eluent in the ratio of 1:9 (1.0mL ethylacetate and 9.0mL hexane). As seen in the picture (left), not much movement of the molecules were observed. Hence, new eluent for TLC was prepared with ethylacetate:hexane ratio of 1:2 (5mL and 10mL respectively). As seen in the middle of the picture, the result was better, but still not clear distinction, so another TLC was run will similar eluent, but this time the samples with diluted with acetone. The right TLC plate in the picture shows the result.

It is clear that the product does contain some picolinic acid and phenylisocyanate, but another method to analyse the product is required for detailed understanding.

Chemical dip method was done on the TLC plate, but no new spots were formed.

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Characterizing N-4-phenyl picolinamide

he NMR spectrum of KG01 and KG02 were taken. The products were insoluble in CDCl3, so acetone was used as a solvent for obtaining NMR spectrum.

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ImageFrom the graphs it is clear that both, KG01 and KG02, are same product. However, clearly the products are not the ones we expected as the number of peaks are too few for N-4-phenyl picolinamide molecule. One of the possibilities is that since water was involved in the reaction (which I accidentally added in place of acetone), the N-4-phenyl picolinamide could have broken down into picolinic acid and aniline. The picolinic acid could have been washed away with water leaving aniline, so there is a probability that the spectrum is of aniline, and it does seem consistent; aniline has 4 different hydrogen environment, there are 4 major peaks with two triplet and a doublet.

Naked Egg Experiment

In this experiment, we were showing how Acetic Acid and Hydrochloric Acid can be used to dissolve the shell of an egg. The calcium carbonate in the egg shell reacts with the acid to form a salt, water, and carbon dioxide. We started by diluting the stock 15M Acetic Acid and 12M Hydrochloric Acid to the molarities that we wanted. We used 250mL of four different concentrations of each acid (Table 1).

Acid Molarity Amount of stock acid used
CH3COOH 0.435M 7.25mL
0.87M 14.5mL
1.74M 29mL
3.48M 58mL
HCl 0.1M 2.08mL
0.2M 4.16mL
0.5M 10.42mL
1.0M 20.83mL

Overall we used 108.75mL of stock Acetic Acid. Acetic Acid is $58.00 per Liter, meaning that we used about $6.30 of Acetic Acid. We used 37.49mL of Hydrochloric Acid. HCl is $41.00 per 500mL, so we used about $3.07 of HCl. setup

Above is the display set up. At this point all of the eggs still had their shells and were the same as they were in the package.  In day 1, pictures below, all of the eggs formed bubbles around the shells. Up close you could hear the gas, CO2 trying to escape the jar. All of the eggs still had the shell and looked the same at this time..5M HCl start

After week one there was some significant changes in the eggs.0.87 Acetic 1week

.1 M HCl: The shell on the egg did not do anything and when it was broken open it looked exactly like one that came out of the carton.

.2 M HCl: This egg cracked so we were unable to observe the results.

.5 M HCl: The shell dissolved completely, leaving only the membrane. The egg also denatured and cooked inside because of the acid.

1 M HCl: The egg completely denatured and was hard inside. The shell had dissolved and only the egg’s membrane was left

.435 M CH3COOH: The egg shell halfway dissolved. The egg was still white but it bounced.

.87 M CH3COOH: The shell off the egg dissolved completely and the egg and it was able to bounce.

1.74: The shell off this egg turned into a rubber material, but it did dissolve. This is why it is white in appearance. This egg also bounces slightly.

3.48 M CH3COOH: This egg denatured just like the .5 M and 1 M HCl.

N-4-phenyl picolinamide -Gurung

In this experiment, we are trying to create one branched, N-4-phenyl picolinamide molecules from the reaction between picolinic acid and pheylisocyanate in presence of amine, diisopropylethylamine and solvent DMF, under standard conditions.

Reactant:

Reactant Used Ratio
Picolinic acid 0.932g 1.5
Phenylisocyanate 0.548ml 1
N,N-diisopropylethylamine 1.76ml 2

Synthesis:

Reactant Used Ratio
Picolinic acid 0.936g 1.5
Phenylisocyanate 0.550ml 1
N,N-diisopropylethylamine 1.757ml 2
DMF (Solvent) 245.40ml

Observation:

10th Sept 2012

Picolinic acid was dissolved in DMF, the resulting solution was colorless solution, followed by addition of isocyanate, which turned the solution to yellow, then we added the amine N,N-diisopropylethylamine, which did no visual change to the solution. The solution was left to mix overnight.

Added at 15:20

17th Sept 2012

Under vacuum, attempt was made to remove the solvent, DMF, from the solution, but since it took long time, it was left to evaporate in air overnight.

Started at 17:45

19th Sept 2012

After two days all the solvent had already evaporated, leaving pale while/yellow sold at the flask.

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24th Sept,2012

The solid was to be dissolved in methanol for TLC, but unfortunately an error was made where I added water instead of methanol. Then, I added methanol on the solution so that it was 50/50 water and methanol and proceeded with heating the solution. On heating all the solid particles dissolved.

The solution was then put in ice to induce crystallization. Few crystals were formed. After that, the crystallization was done under vacuum. The solid collected in the filter paper was labelled KG01.

Formation of crystals were also observed in the filtrate, so we proceeded to crystallize the solute from the filtrate under vacuum in second erlenmeyer flask, and the crystal obtained was labelled KG02.

25th Sept,2012

To test where the crystals were expected products or not, their melting ranges were taken and was found to be 228-234oC for both KG01 and KG02, which is pretty high than of N-4-phenyl picolinamide,72.6-74.0oC (ref. Sasaki, Crich.) we are trying to synthesize. This is also intriguing because none of the reactants also have such high melting range.

Chemical Melting point/range (oC)
Picolinic acid 137
Phenylisocyanate -30
N,N-Diisopropylethelamine <-50

source: MSDS sheet, http://www.sciencelab.com

Hoping that the expected products were still in the filtrate obtained from crystallization, I initiated evaporation of liquid to in air obtain the solid product (along with other possible impurities.)

3rd Sept,2012

All the liquid had evaporated leaving pale white/yellow solid similar to the one obtained at 19th Sept 2012.

The solid was dissolved in methanol, giving orange solution, and TLC test was conducted with solvent of 95% dichloromethane and 5% methanol.

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The sample does contain mixture of particles.

By looking at Dr Bodwin’s similar experiment and TLC of his sample in similar solvent,

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it’s reasonable to say the product is between the two reactants (bottom two in the plate), and it seems acetone (the top one), can get ride of those two reactants leaving the product.

Right now what we have left to do is to separate the product and find out it’s structure, and possibly of also KG01 and KG02.

N-4-phenyl picolinamide {JBE0105}

N-4-phenyl picolinamide JBE0105

2012/09/08

Planning:

This is the 1-armed version of the ligands we’ve been trying to make. This synthesis is from {Organic Letters, 2011, 13, 9, 2256-2259, Kaname Sasaki and David Crich*} It looks like a pretty simple reaction between the carboxylic acid precursor (picolinic acid) and an isocyanate (phenylisocyanate) with an amine base.

Reactant Amount Moles Ratio
Picolinic acid 100mg C6H5O2N, 123.111g/mol 8.12mmol 1.5
Phenylisocyanate 0.59mL 1.096g/mL, C7H5NO, 119.12g/mol 5.42mmol 1
N,N-diisopropylethylamine 1.89mL 129.24g/mol, 0.742g/mL 10.84mmol 2
N,N-dimethylformamide (DMF) 40mL 10mL/mmol isocyanate

From the article, dissolve acid and amine in DMF, add isocyanate (single portion) and stir at 25°C for 2 hours. Remove volatiles under vacuum, purify by prep TLC (99:1 mix CHCl3:MeOH), white needles, Tm=72.6-74.0°C. Hopefully by scaling up it will crystallize without prep TLC.

Synthesis:

Reactant Amount Moles Ratio
Picolinic acid 110mg C6H5O2N, 123.111g/mol 0.894mmol 1
Phenylisocyanate 0.65mL 1.096g/mL, C7H5NO, 119.12g/mol 5.98mmol 6.7
N,N-diisopropylethylamine 2.0mL 129.24g/mol, 0.742g/mL 11.5mmol 13
DMF 25mL 10mL/mmol isocyanate

Combined picolinic acid and amine in DMF, stirred to dissolve at room temperature. Added phenylisocyanate as a single addition, slight orange color developed almost immediately. Addition at 8:25, 2012-09-08. Left to stir at RmTemp. RmTemp is always a bit less than 25degC and since the rxn is scaled up, it can react a bit longer. Color faded to pale yellow over a few hours.

2012-09-10 – ERROR – There was a decimal place mix up here. There should be MUCH more picolinic acid. Since the rxn is run at Rm Temp, I’ll try to salvage it by adding more and letting the rxn go a bit longer. Arg. Need 0.998g more picolinic acid.

Synthesis:

Reactant Amount Moles Ratio
Picolinic acid 0.110+1.000= 1.110g C6H5O2N, 123.111g/mol 9.02mmol 1.5
Phenylisocyanate 0.65mL 1.096g/mL, C7H5NO, 119.12g/mol 5.98mmol 1
N,N-diisopropylethylamine 2.0mL 129.24g/mol, 0.742g/mL 11.5mmol 1.9
DMF 25mL 10mL/mmol isocyanate

Additional picolinic acid added 14:30, 2012-09-10.

Open Notebooking/Live Blogging/#RealTimeChem

This is a new experiment for me. Inspired by a number of factors, my research students and I will be keeping open lab notebooks of the research we do at Minnesota State University Moorhead. This will allow everyone to see the great work we do here and will be a good way to keep ourselves up-to-date. The majority of the work posted here will be tentative and some of it may end up being just plain wrong, but that’s one of the exciting parts of science.