Benzaldehyde is a precursor to a huge number of organic compounds. Synthesis in a high yield at a low cost is the ultimate goal. Expensive reagents are to be avoided. Bonus points for doing it quickly.
Chromyl Chloride and Dichloromethane
Attempt by Dennis Phillips aka NileRed: 51% yield (Dennis Phillips 2017)
Benzoic Acid and Hypochlorite
- 12% yield based on Benzoic Acid. (Scott Daniel 2017)
Sodium Persulfate and Iron-Copper Catalysts
Ferrous-Copper Catalyst: Toluene (7.6 g.), water (35 ml.), ferrous sulphate (0.110 g.) heptahydrate, cupric acetate (0.072 g.) and methanol (8 ml.) are placed in a 250 ml. reactor.
Sodium persulphate (47.05 g.) in an aqueous-methanol solution of sodium persulphate is added slowly to the mixture which is maintained at 70° C., in an atmosphere of nitrogen and under agitation.
The organic phase is separated after two hours and the aqueous phase is extracted with ethyl ether.
The combined organic phases are distilled to afford 8.29 g. (95% yield) of very pure benzaldehyde (compared against a pure sample). (Maggioni 1979)
Attempt by sum_lab gave single-digit yields. (sum_lab 2018)
Attempt by NileRed yielded 10% on weight basis of cinnamon oil. (NileRed 2016)
13 Jul 2018
- started research on various methods used in the literature
- fiddled with Marvin for 5 hours: Chemdraw is wayyyy better
Dennis Phillips. 2017. “Making Benzaldehyde (Étard Reaction).” https://www.youtube.com/watch?v=L8kFJPEZdwM.
Maggioni, Paolo. 1979. Process for preparing aromatic aldehydes and ketones. US4146582A, issued March 1979. https://patents.google.com/patent/US4146582A/en?oq=4\%2c146\%2c582.
NileRed. 2016. “Making Benzaldehyde (from Cinnamon Oil).” https://www.youtube.com/watch?v=Fui19FPh0R0.
Scott Daniel. 2017. “Benzaldehyde via Hypochlorite Oxidation of Benzyl Alcohol.” https://www.youtube.com/watch?v=ExogvX4vD78.
sum_lab. 2018. “Benzaldehyde Attempt 1.” https://www.youtube.com/watch?v=G_PSJAtfmso.