Carvacrol may be synthetically prepared by a number of routes. The fusion of cymolsulfonic acid with caustic potash results in desulfonation. By the action of nitrous acid on 1-methyl-2-amino-4-propyl benzene, one effects diazotization. Prolonged heating of camphor and iodine or carvone with glacial phosphoric acid have also been demonstrated. The dehydrogenation of carvone with a palladium-carbon catalyst has been established.[5]
It is extracted from Origanum oil by means of a 50% potash solution. It is a thick oil that sets at -20 °C to a mass of crystals of melting point 0 °C, and boiling point 236–237 °C. Oxidation with ferric chloride converts it into dicarvacrol, whilst phosphorus pentachloride transforms it into chlorcymol.[5]
^ abBouchra, C.; Achouri, M.; Idrissi Hassani, L. M.; Hmamouchi, M. (2003). "Chemical composition and antifungal activity of essential oils of seven Moroccan Labiatae against Botrytis cinerea Pers: Fr". Journal of Ethnopharmacology. 89 (1): 165–169. doi:10.1016/S0378-8741(03)00275-7. PMID14522450.
^Liolios, C. C.; Gortzi, O.; Lalas, S.; Tsaknis, J.; Chinou, I. (2009). "Liposomal incorporation of carvacrol and thymol isolated from the essential oil of Origanum dictamnus L. and in vitro antimicrobial activity". Food Chemistry. 112 (1): 77–83. doi:10.1016/j.foodchem.2008.05.060.
^ abAligiannis, N.; Kalpoutzakis, E.; Mitaku, S.; Chinou, I. B. (2001). "Composition and antimicrobial activity of the essential oils of two Origanum species". Journal of Agricultural and Food Chemistry. 49 (9): 4168–4170. doi:10.1021/jf001494m. PMID11559104.
^Coşkun, Ş.; Girişgin, O.; Kürkçüoğlu, M.; Malyer, H.; Girişgin, A. O.; Kırımer, N.; Başer, K. H. (2008). "Acaricidal efficacy of Origanum onites L. essential oil against Rhipicephalus turanicus (Ixodidae)". Parasitology Research. 103 (2): 259–261. doi:10.1007/s00436-008-0956-x. PMID18438729. S2CID5771248.
^Ruberto, G.; Biondi, D.; Meli, R.; Piattelli, M. (1993). "Volatile flavour components of Sicilian Origanum onites L.". Flavour and Fragrance Journal. 8 (4): 197–200. doi:10.1002/ffj.2730080406.
^Kanias, G. D.; Souleles, C.; Loukis, A.; Philotheou-Panou, E. (1998). "Trace elements and essential oil composition in chemotypes of the aromatic plant Origanum vulgare". Journal of Radioanalytical and Nuclear Chemistry. 227 (1–2): 23–31. doi:10.1007/BF02386426. S2CID94582250.
^Figiel, A.; Szumny, A.; Gutiérrez Ortiz, A.; Carbonell Barrachina, Á. A. (2010). "Composition of oregano essential oil (Origanum vulgare) as affected by drying method". Journal of Food Engineering. 98 (2): 240–247. doi:10.1016/j.jfoodeng.2010.01.002.