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Author: Subject: n-propanol to propionaldehyde
CuReUS
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[*] posted on 2-10-2015 at 01:54


why don't you try the oxidation using lead tetracetate/Pyridine.It can be done at room temperature and I think triethylamine could be used instead of pyridine.
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Mush
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[*] posted on 17-10-2020 at 13:06


1-propanol from methyl-propionate

Methyl propanoate synthesis:
Propanoic acid 50 mL (0.67 mole), methanol 20 mL (0.5 mole) and two mL sulfuric acids were added in the reflux system. The mixture was refluxed and stirred with a magnetic stirer for 14 h. The product was distilled at a temperature of 70-80 °C. Then, it was extracted with ten mL of 10% NaHCO3. The bottom layer was separated, and the top layer is dried with anhydrous Na2SO4. The product was weighed and analyzed by GC, IR and 1H-NMR Yield: 33 g (0.4 mole)

1-Propanol synthesis:
Methyl propanoate 5 mL (0.045 mol) was added in a 100 mL three neck flask with 10 g (0.45 mol) of natrium. The mixture is stirred with a magnetic stirrer and heated with an oil bath. After sodium melting, we added ethylene glycol as a solvent. (Added as soon without removing the reflux system). The mixture was refluxed for one hour. The product was distilled at the temperature of 90-100 °C. The product was weighed and analyzed by GC. Yield: 2.2 g (0.035 mol).

https://www.researchgate.net/publication/313590165_Synthesis...
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[*] posted on 17-10-2020 at 19:38


https://www.youtube.com/watch?v=T9ha_MS1S9o&t=132s
This technique (dichromate, and boil off the aldehyde before its further oxidized to carboxylic acids) works because the boiling point of the aldehyde is far lower than either the alcohol or the carboxylic acid, due to lack of OH groups for hydrogen bonding.

works for acetaldehyde and low MW aldehydes, but gets more difficult with higher MW alcohols -> aldehydes as the boiling points of the aldehydes and carboxylic acids get closer together. When converting large alcohols to large aldehydes, you would use a synthetic technique for converting alcohols to aldehydes, such as pyridinium chlorochromate, DMP reagent, swern oxidation.

[Edited on 10-18-2020 by Cou]




my youtube channel, organic chemistry videos: https://www.youtube.com/channel/UC0qzaRyHxLUOExwagKStYHw
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