Hi Friends,
I am getting quite busy with my schedule, which is the reason I am not getting time to write my experiments. I will try to write them as soon as possible. Don’t worry I have them jotted down in my notes, but just not on the mahine. I will hopefully get them typed or probably write it on my own. Things are going good… Had my first chemical kick yesterday… The material frothed out of the condenser 
. Anyways, wish me luck guys!! Bye!
JPV
Found a convinient methylation process. Going to try out that agaisnt the one with methly iodide… Here is the process…
Gallacetophenone 3,4-dimethyl ether
To a boiling mixture of gallacetophenone (16.8g, 1 mol), benzene (400 mL) and anhydrous K2CO3 (55g) was added methyl sulphate (26.5g, 2.05 mol) in one portion, and the whole refluxed for 6 h with occasional shaking. After the addition of water (750 mL) and shaking, the benzene layer was separated and shaken several times with NaOH solution, and the alkaline extracts solidified. The precipitated gallacetophenone 3,4-dimethyl ether after crystallisation from MeOH had mp 75-77°C (yield 10g) (for previous methods of preparation from gallacetophenone, see Perkin9, Perkin and Wilson10, David and von Kostanecki11).
I found this interesting. I think it should be easier 
. The work up is much easier. No column atleast
Today was a good day! I learned a lot from the research reactions that I have been carrying out. Its really a great learning exprience. Okay, today what I did was methylation of my product that I have synthesized earlier. I have described the product synthesis here. Let me call the reactant “A”. Okay, here is what I did. I took up 5 ml of acetone in a test tube. I took about 0.5 g of “A” in the test tube. The compound got dissolved and formed a light yellow solution. To that, about 0.2 g of K2CO3 was added. This resulted into a little bit of extra K2CO3 remaining undissolved. The test tube was shaked vigorously and I tried to make sure that the K2CO3 dissoved as much in the reaction mixutre as possible. After about 5 minutes of vigorous shaking and breaking of K2CO3 with a glass rod, quite a bit of K2CO3 had dissolved. After that about 0.2 ml of methyl iodide was added to the reaction mixture. This resulted into deepening of the yellow colour of the reaction mixture. The temperature of the test tube rose by about 1 C. I will check the results of the tests by tomorrow. Hopefully, it would give me something to cheer about!
Here pyrogallol reacts with Acetic Anhydride in presence of Zinc Chloride (Lewis Acid) and acetic acid as a solvent.
Pyrogallol:
- IUPAC Name: benzene-1,2,3-triol
- Chemical Formula: C6H6O3
- Exact Mass: 126.03
- Molecular Weight: 126.11
- m/z: 126.03 (100.0%), 127.04 (6.7%)
- Elemental Analysis: C, 57.14; H, 4.80; O, 38.06
- Boiling Point: 309°C
- Melting Point: 131-134 °C
- Critical Temp: 792.92 [K]
- Critical Pres: 99.8 [Bar]
- Critical Vol: 311.5 [cm3/mol]
- Gibbs Energy: -342.18 [kJ/mol]
- Log P: 0.87
- MR: 30.72 [cm3/mol]
- Henry’s Law: 12.61
- Heat of Form: -451.1 [kJ/mol]
- tPSA: 60.69
- CLogP: 0.211
- CMR: 3.1479
Gallacetophenone:
- IUPAC Name: 1-(2,3,4-trihydroxyphenyl)ethanone
- Chemical Formula: C8H8O4
- Exact Mass: 168.04
- Molecular Weight: 168.15
- m/z: 168.04 (100.0%), 169.05 (8.9%), 170.05 (1.2%)
- Elemental Analysis: C, 57.14; H, 4.80; O, 38.06
- Boiling Point: 705.05 [K] (Calc)
- Melting Point: 171-172 °C
- Critical Temp: 828.83 [K]
- Critical Pres: 76.28 [Bar]
- Critical Vol: 429.5 [cm3/mol]
- Gibbs Energy: -463.89 [kJ/mol]
- Log P: 0.18
- MR: 41.97 [cm3/mol]
- Henry’s Law: 15.35
- Heat of Form: -616.43 [kJ/mol]
- tPSA: 77.76
- CLogP: 0.861434
- CMR: 4.1112
Synthetic Procedure:
In a 250-cc. round-bottomed flask, fitted with a reflux condenser, 28 g. (0.21 mole) of freshly fused zinc chloride is dissolved in 38 cc. of glacial acetic acid by heating in an oil bath at 135–140°. Try to make sure that the quality of Zinc Chloride used is good. It is always preferred to freshly fused Zinc Chloride. The temperature of the solution remains close to about 132 °C. Once the temprature reaches this point, forty grams (0.37 mole) of 95 per cent acetic anhydride is then added to the clear, pale brown liquid, followed by the addition in one lot of 50 g. (0.4 mole) of distilled pyrogallol. The addition should be done only after about 30 minutes of free stirring of pale brown liquid. The mixture is heated at 140–145° (Note 3) for forty-five minutes with frequent and vigorous shaking. Once again, due to the acetic acid synthesized in the reaciton, the temprature of the flask should not exceed 138 °C. You can try to maintain the bath temperature at 150°. The unused acetic anhydride and acetic acid are removed by distilling under reduced pressure. The temperature should NOT exceed 150 °C. The red-brown cake is broken up by the addition of 300 cc. of water with mechanical stirring for a few minutes. The mixture is cooled in ice water, filtered with suction, and washed with cold water. The crude material, 45–50 g., is crystallized from 500 cc. of boiling water saturated with sulfur dioxide. The yield of straw-colored needles melting at 171–172° is 36–38 g. (54–57 per cent of the theoretical amount). On saturating the mother liquor with salt and cooling to 10°, 4–5 g. of crude material is obtained, which on recrystallization yields 3–4 g. of pure material.
The method described above is a modification of the process of Nencki and Sieber. Gallacetophenone has also been prepared by treating pyrogallol with acetyl chloride, and from 2-formyl-4-acetylresorcinol by treatment with hydrogen peroxide and alkali.
Related References:
- Witt and Braun, Ber. 47, 3227 (1914).
- Cheema and Venkataraman, J. Chem. Soc. 1932, 919.
- Nencki and Sieber, J. prakt. Chem. (2) 23, 151, 538 (1881);
- Nencki, Ber. 27 2737 (1894).
- Crabtree and Robinson, J. Chem. Soc. 121, 1038 (1922).
- Einhorn and Hollandt, Ann. 301, 107 (1898);
- Fischer, Ber. 42, 1020 (1909).
- Nakazawa, J. Pharm. Soc. Japan 59, 297 (1939) [C. A. 33, 8186 (1939)].
What I am going to do from now on, is probably write down every thing I research. I will try to be as regular as I can be in the course of my writing. Let me begin with writing about the reaction that I carried out the other day. See you soon!
