[vanillin.eugenol.demethylation.methylation] [2-heac.nitroaldol.condensation] [nabh4.copper.reduction] [zn.hcl.reduction] [back]
Piperonal and Safrole from Vanillin and Eugenol, www.rhodium.ws| 20g Ethyl vanillin(144 mmol) was added to 142.2g H2SO4 (1440 mmol, 78ml) of 5C in a 250ml erlenmeyer, under an 9argon stream (was not done the first 2 minutes, and immediately there was discoloration). Next, the temperature was raised to 65-70 degrees C; after an additional 5.5 hours of stirring heated at the same temperature, the reaction liquid was cooled to room temperature. Then, to the thus obtained reaction liquid was added, with stirring, ice water (150ml) and the reaction liquid stirred for 20 min. A precipitate formed. RM was transferred to a new container (500ml Erlenmeyer), 100 ml water was added, and it was extracted first with 160ml diethyl ether (100 was not enough at 17C, 140 probably) and then 70 more. Organic phase is washed to pH7 and evaporated. The second extract was almost clear, while the first had a pink color, like the aqueous phase. Yield is 9g (54%), pink powdery crystals. |
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| name | molweight | cas number | melting point |
|---|---|---|---|
| 3-ethoxy-4-hydroxybenzaldehyde (substrat) | 166.18 | 121-32-4 | 76-78 |
| 3,4-dihydroxybenzaldehyde (product) | 138.12 | 139-85-5 | 153-155 |