Trimyristin from nutmeg

Trimyristin, or glyceryl trimyristate, is an interesting triglyceride that occurs naturally in nutmeg. It doesn't have many uses except in scientific research. Trimyristin can be hydrolysed to glycerol and myristic acid, and in the future I plan to try this out. Ground dry nutmeg typically contains about 25% trimyristin (by weight) so this is a great source of the compound.

The extraction of trimyristin from nutmeg is a classic experiment. Usually diethyl ether is used as the extraction solvent, but I tried using a different method.

To a 250ml conical flask, I added 40g of dry ground nutmeg. To this I added 100ml of hot (nearly boiling) ethanol and stirred vigorously for 15 seconds. I then immediately filtered the mixture through a cloth, collecting the orange filtrate in a 200ml conical flask. I washed the nutmeg on the filter with 25ml more hot ethanol. It's important that the whole filtering process is performed quickly while the ethanol is still hot, otherwise the trimyristin will start crystallizing out. Anyway, the 200ml conical flask containing the filtrate (already starting to precipitate some product) was chilled to about 2 C. A lot more trimyristin crystallized out and the mixture was filtered to collect it.

After filtration, I was left with fine crystals of almost white trimyristin. I decided to perform a recrystallization from ethanol to purify my product. After recrystallization, I was left with 0.84g of trimyristin as very fine white crystals. The product was easily melted by hot water, which is a good sign as trimyristin is said to melt at about 56 C. My guess is the trimyristin isn't extremely pure but still definitely usable for most things.

Left = recrystallized trimyristin   Right = ground nutmeg

This extraction was poorly planned and performed. I probably could have gotten more product by boiling the nutmeg in ethanol at the start. My procedure was loosely based on this.

Ammonoylsis of diethyl oxalate to oxalamide

Oxalamide or ethanediamide, is an organic compound used as a fertilizer. It's also used as an additive in some rocket fuel mixtures to help slow the burning rate. At room tempurature, oxalamide exists as a white solid. When heated past 350 C, it decomposes releasing deadly cyanogen gas. I did plan to use oxalamide for an experimental synthesis of cyanoformamide, but I decided that this was too dangerous.

Oxalamide can be made by the ammonoylsis of diethyl oxalate. This is a quick and very easy synthesis.

First I added 24ml of 25% aqueous ammonia solution to a 100ml beaker. Then using a syringe, I added 10ml of diethyl oxalate. At first the diethyl oxalate just formed a bottom layer, but after a few seconds, I noticed a white precipitate (presumably oxalamide) beginning to form. I began stirring the mixture and rapidly more oxalamide precipitated. The mixture got thicker as the precipitate built up. After about 1 minute of stirring, the mixture had become a thick white paste. Once this point was reached, I transferred the pasty mixture on to a sheet of paper to dry. After drying, I was left with 6.42g of a white powder, which is almost definitely oxalamide. If pure, this represents a 99% yield!

 A nice feature of the reaction is that oxalamide is the only non-volatile solid involved. This means a fairy pure product can (in theory) be obtained just by allowing the mixture to dry. The only thing that could contaminate the product is unreacted diethyl oxalate. For this reason, I used a 10% excess of ammonia solution to ensure all the diethyl oxalate reacted.


(C2H5)2C2O4 + 2 NH3 ==> (CONH2)2 + 2 C2H5OH

Diethyl oxalate

Diethyl oxalate, or diethyl ethanedioate, is a interesting ester used as an organic building block. It has an ethereal smell similar to grape juice. Diethyl oxalate is also used as a specialty solvent for various resins, and as a pigment carrier. In the pharmaceutical industry, diethyl oxalate is used to produce barbiturate steroids. I plan to use it to prepare ethyl acetopyruvate and oxalamide. Diethyl oxalate can be made from dry ethanol and anhydrous oxalic acid. I tried this out.

To get a good yield, the hydrated oxalic acid used must be made anhydrous.

To a large crystallizing dish, I added 100g of oxalic acid dihydrate. I then placed the crystallizing dish
on a hotplate and lowered in an overhead thermometer. I heated the oxalic acid at around 140 C until no more water boiled off. During this process, the oxalic acid melted and a large amount of vapor
(mostly steam) was boiled off. This is not a very effective way to produce anhydrous oxalic acid, but I got there in the end.

To a 500ml round-bottom flask, I added the anhydrous oxalic acid prepared above. I then added 200ml of ethanol and a drop of 98% sulphuric acid, then set up for reflux. I allowed the mixture to reflux for 2 hours. The anhydrous oxalic acid dissolved but apart from this, there was not much visible change in the mixture. After 2 hours of reflux, I removed the condenser and set up for simple distillation. The first fraction came over at 71-81 C,  consisting of ethanol/water azeotrope. About 175ml of this was collected. The temperature of the distillate then rose to 100 C, and I changed the receiving vessel. I kept collecting distillate until nothing was left in the distilling flask. The temperature had climbed to 220 C at the end of the distillation. I had collected 50ml of clear liquid, predominantly diethyl oxalate.

To this liquid, I added 60ml of saturated sodium chloride solution. I shook the mixture up then let it settle. The diethyl oxalate separated, forming a layer above the surrounding liquid. I collected the diethyl oxalate product with a syringe, dried it over anhydrous calcium chloride and finally transferred it to an amber glass bottle for storage. I got 42ml of diethyl oxalate which is a 34% yield.


Adding a drop of sulphuric acid isn't absolutely required as oxalic acid is a strong enough acid to catalyse the reaction.

H2C2O4 + 2 C2H5OH ==(- H2O)==> (C2H5)2C2O4 + 2 H2O

2-Aminophenol via hydrolysis

2-Aminophenol, or 2-hydroxyaniline, is an organic compound used in photography. It's a valuable reagent used to synthesize many heterocyclic compounds such as benzoxazoles (many of which are important in the pharmaceutical industry). I plan to use 2-aminophenol to synthesize catechol. Although I'm not sure if I'll ever get around to it.

2-Aminophenol is formed via the acid hydrolysis of 2-benzoxazolinone. I tried this out.

To a 500ml round bottom flask, I added 27ml of 33% hydrochloric acid and 70ml of water. I then added 1.8g of 2-benzoxazolinone and set up for reflux. Using a boiling water bath as the heating source, I gently refluxed the mixture for 2 hours. The 2-benzoxazolinone gradually dissolved leaving a clear brown-yellow solution. After the reflux, I allowed the mixture to cool down to room temperature. As the mixture cooled, fluffy white crystals of 2-aminophenol began to precipitate.

Once the mixture had fully cooled, I filtered off the 2-aminophenol product. After drying I was left with 0.62g of slightly brown 2-aminophenol which is a 42.6% yield.

A note on safety: although the deadly gas phosgene is produced in this reaction, it immediately reacts with the water present as soon as it is formed. Due to this, the risk of phosgene poisoning is extremely low.


C6H4(O)NHCO + 2 HCl ==> C6H4(OH)NH2 + COCl2  /  COCl2 + H2O ==> CO2 + 2 HCl

1,3,5-Trimethylbenzene

1,3,5-Trimethylbenzene commonly called mesitylene, is an aromatic hydrocarbon occasionally used as a ligand or solvent. Its also used as an additive to plane fuel and as a precursor to 2,4,6-trimethylaniline. Upon mild oxidation with Manganese dioxide, mesitylene forms 3,5-Dimethylbenzaldehyde, I may have a post on this in the future. Mesitylene can be made by the dehydration of acetone with sulphuric acid. I tried this method out.

To a 1000ml round-bottom flask in an ice bath I added 127ml of acetone. Once the acetone had cooled to 5 C, I (over the course of 5 hours) began adding 90ml of 98% sulphuric acid in small portions. I made sure the temperature never rouse above 22 C during the additions. Towards the end of this, the mixture started becoming red in colour. I left the mixture to stand for 24 hours then set up for simple distillation. as the distillation progressed a green liquid started coming over. Soon after this, huge amounts of sulphur dioxide started being generated. The distillation setup must be equipped with a gas outlet to dispose of the toxic sulphur dioxide. Anyway, after a few minutes, a yellow oil began to come over. it formed a layer on top of the previous distillate. I presumed this was the crude mesitylene.

I stopped the distillation when the foam in the distilling flask reached the bottom of the still-head.
Using a syringe I collected the top mesitylene layer in the receiving flask. I washed the mesitylene with 20ml of dilute sodium hydroxide solution, then dried it over anhydrous calcium chloride.
I then distilled the crude product collecting the fraction boiling at 100-200 C. As I was collecting the mesitylene distillate I accidentally spilled some. Due to this I only got 3ml of mesitylene product and my yield was 2.1%. The procedure I followed claimed a 25% yield.

3 (CH3)2CO  ==H2SO4==>  C6H3(CH3)3 + 3 H2O

Sodium pyroantimonate

Sodium pyroantimonate is an interesting salt used as a glass clarifier. It's also used in monochrome picture tubes and glass fibers. At room temperature, sodium pyroantimonate exists as white crystals.
I chose to make it because the synthesis seemed interesting. I probably won't use the product for anything though.

To a 125ml beaker I added 20ml of 35% (by weight) sodium hydroxide solution. Next I added 4g of crude antimony trisulphide. The antimony trisulphide dissolved giving a brown-yellow solution. Slight heating was needed to get all of it dissolved. Since my antimony trisulphide was impure, some elemental antimony remained. This was filtered off before continuing. The solution was transferred to a 1000ml conical flask and diluted with 130ml of water. I heated the mixture up to 70 C and slowly added 50ml of 6% hydrogen peroxide in portions with stirring while maintaining the temperature at 70-85 C. The colour of the mixture changed to a light yellow and some crystals of sodium pyroantimonate precipitated. I let the mixture cool down to room temperature then filtered off the sodium pyroantimonate.

 I washed the product with 10ml of equivolume water/ethanol mixture and then 10ml of anhydrous ethanol, then dried it. I got 1.5g of dry sodium pyroantimonate.

Sb2S3 + 6 NaOH ==> Na3SbS3 + Na3SbO3 + H2O

3 H2O + Na3SbO3 + H2O2 ==> NaSb(OH)6 + 2 NaOH

 NaOH + H2O2 + Na3SbS3 + 3 H2O ==> NaSb(OH)6 + 3 NaSH

Preparation of mixed polysulphanes

Polysulphanes are interesting compounds. At room temperature they exist as toxic yellow liquids. The three stable polysulphanes are disulphane, trisulphane and pentasulphane. They are all very sensitive to alkalies so the glassware used to make these compounds must be washed with acid to remove trace amounts of alkali. They have few applications and uses.

I decided to try making disulphane. The reaction produces all three polysulphanes. In a future post I will perform a distillation to isolate disulphane.

The first step is to prepare a solution of sodium polysulphides.

To a 500ml beaker, I poured a solution containing 17g of sodium hydroxide and 150ml of water. I added in 20g of sulphur and began boiling the mixture. The sulphur gradually dissolved and the mixture turned a beautiful dark red colour. After all the sulphur had dissolved, 120ml of dark red liquid were left. This is the polysulphide solution.

Next the sodium polysulphides must be acidified to yield the polysulphanes. All equipment used in this procedure was washed with 5% acetic acid to prevent decomposition of the polysulphanes.

In a 500ml beaker, I chilled down 20ml of the solution prepared in step one to 0 C. The reaction is best performed at -15 C but 0 C was as cold as I could get. After this temperature had been reached, I added the solution to 60ml of 33% hydrochloric acid (also chilled to 0 C). If the starting solution and the acid aren't chilled, only hydrogen sulphide and sulphur will be formed. Anyway, after the addition, a bit of hydrogen sulphide was produced along with some solid sulphur. I stirred the mixture then let it settle. After this, the polysulphanes could be seen as a vivid yellow liquid at the bottom of the container separate from the surrounding liquid. 

The product was collected with a syringe and placed in an acid-washed vial. I got 0.7ml of mixed polysulphanes.

S8 + 12 NaOH = 4 Na2S + 2 Na2S2O3 + 6 H2O  /  S8 + 4 Na2S = 4 Na2S3

S8 + 8 Na2S = 8 Na2S2  /  S8 + 2 Na2S = 2 Na2S5  /  Na2Sx + 2 HCl = H2Sx + 2 NaCl