Thymol 5-methyl-2- phenol

Higher homologues of phenol include thymol (2-isopropyl-5-methyl phenol) and its isomer carvacrol (5-isopropyl-2-methyl-phenol)... 

Thymol, isopropyl meta-cresol, is a precursor of L-menthol. Meta-cresol with a purity of >98.5% must be used as the starting material for thymol production, because the isomer, 2-iso-propyl-4-methyl phenol derived from p-cresol is the main contaminant and cannot be easily separated from thymol. 

Styrene (99%, Nacalai Tesque, Japan), MMA (99%, Nacalai), and azobis(isobutyronitrile) (AIBN) (99%, Nacalai) were purified by distillation or recrystallization. 1-Phenylethyl iodide (PE-1) and 2-cyanopropyl iodide (CP-1) were prepared according to Matyjaszewski (9) and Balczewski (10), respectively. 2,2 -Azobis(2,4,4-trimethylpentane) (VRllO) (99.9%, Wako Pure Chemical, Japan), f-butyl peibenzoate (BPB) (98%, Aldrich), di(4-f-butylcyclohexyl) peroxydicarbonate (PERKADOX16) (95%, Akzo), thymol iodide (TI) (95%, Wako), 2,4,6-trimethyl phenol (2,4,6-Me) (97%, Wako), 2,6-di-f-butyl-4-methyl phenol (3,5-di-f-butyl-4-hydroxy toluene (BUT)) (98%, Wako), 2,6-di-i-butyl-4-methoxy phenol (3,5-di-i-butyl-4-hydroxy anisole (BHA)) (97%, Aldrich), phenol (99%, Wako), vitamin E (VE) (99.5%, Wako), vitamin C (VC) (99%, Tokyo Kasei, Japan), and 2,2,6,6-tetramethylpiperidinyl-l-oxy (TEMPO) (99%, Aldrich) were used as received. 

Winter savory S. montana) contains a volatile oil (1.6%) composed mainly of carvacrol, p-cymene, and thymol (total phenols ca. 50%), with lesser amounts of a-and P-pinenes, limonene, cineole, bomeol, and a-terpineol. It also contains triterpenic acids (ursolic and oleanolic acids). Flavonoids include apigenin, apigenin-4-methyl ether, scutellarein-6,7dimethyl ether, and others. ... 

Thymol is phenolic and is extracted by solutions of fixed caustic alkalis For the same reason it can be determined by the general Koppeschaar method (see Phenol, p. 513), The bromination can be directly estimated by titration, using the bleaching of a solution of methyl orange as an indication of the end-point. ... 

It contains limoaene, ciiral, citronellal, cioeol, and a little thymol, aa well as other nndetermined phenolic constiments. Unlike other Indian basil oils, it contained no methyl-chavicol. 

C18-0102. A solution has a pH of 8.5. What would be the color of the solution if the following indicators were present in the solution (a) methyl orange (b) phenol red (c) bromocresol green and (d) thymol blue (See Table 18-2. )... 

Crystal violet Thymol blue 2,4-Dinitrophenol Bromophenol blue Bromocresol green Methyl red Alizarin Bromothymol blue Phenol red Phenolphthalein Alizarin yellow R... 

Cresol red Crystal Violet Malachite Green Methanil Yellow Thymol Blue Orange IV -2,4-Dinitrophenol -Erythrosin, Na2 salt -Dimethyl Yellow Cl 11020 Bromophenol Blue Congo Red Cl 22120 Methyl Orange Bromocresol Green Alizarin Red S Cl 42750 Methyl Red Cl 13020 -Bromocresol Purple Chlorophenol Red p-Nitrophenol Alizarin Bromothymol Blue Brillant Yellow Phenol Red Neutral Red Cl 50040 -m-NItrophenol -Cresol Red Metacresol Purple Phenolphthalein -Thymolphthalein -P-Naphthyl Violet Alizarin Yellow R 2,4,6-T rinitrotoluene... 

Which indicators could you use for a titration of 0.20 M ammonia with 0.20 M HCl(aq) (a) bromocresol green (b) methyl red (c) phenol red (d) thymol blue Explain your selections. 

Propylamine 1-Propanamine Thymol Phenol, 5-methyl-2-(l-methylethyl)-... 

SYNS P-CYMEN-3-OL 3-p-CYMENOL 3-HYDRO-XY-p-CYMENE 3-HYDROXY-1-METHYL-4-ISOPROP-YLBENZENE ISOPROPYL CRESOL 6-ISOPROPYL-m-CRESOL 2-ISOPROPYL-5-METHYLPHENOL 1-METHYL-3-HYDROXY-4-ISOPROPYLBENZENE 5-METHYL-2-ISOPROPYL-1-PHENOL 5-METHYL-2-(l-METHYLETHYL)PHENOL THYME CAMPHOR THYMIC ACID m-THYMOL... 

Indicator Bromphenol blue Methyl orange Methyl red Bromcresol purple Bromthymol blue Phenol red Cresol red Thymol blue Phenolphthalein Thymolphthalein... 

Addo trimico 3-p-cymenol p-cymen-3-ol Flavinol 3-hydroxy-p-cymene 3-hydroxy-l-methyl-4-isopropylbenzene Intrasol isopropyl cresol isopropyl-w-cresol 6-isopropyl-m-cresol isopropyl metacresol 2-isopropyl-5-methylphenol 1-methyl-3-hydroxy-4-isopropylbenzene 5-methyl-2-isopropyl-phenol 5-methyl-2-(l-methylethyl) phenol Medophyll thyme camphor thymic acid m-thymol timol. 

Nencki introduced salol in 1886 and. so pre.sented to the science of therapy the "salol principle." In salol. two toxic sub.stances (phenol and salicylic acid) were combined into an e.ster that taken internally slowly hydroly/es in the intestine to give the antiseptic action of its components. This type of ester is referred to as a full. salol or true salol when toth components of the ester are active compounds. Examples are guaiacol benzoate. /3-naphthol benzoate, and salol. The salol principle can be applied to esters in which only the alcohol or the acid is the toxic, active or corrosive portion this type is called a partial salol. Examples of partial sulols that contain an active acid arc ethyl salicylate and methyl salicylate. Examples of partial sulols that contain an active phenol are creosote carbonate, thymol carbonate, and guaiacol carbonate. Althtxigh many. salol-typc compounds have been prepared and used tu. some extent, none is presently... 

Main components 1.5-4% essential oil, which contains linalool, bomeol, terpinene -ol, a-terpineol, the methyl ethers of thymol, carvacrol and eugenol, cuparophenol (a phenolic sesquiterpene), sesquiterpene hydrocarbons, cascarilladiene, cascarillone [45, 46] and cascarillic acid ]47], Moreover, cascarilline (bitter constituent), cascaril-line A, vanillic aldehyde, resin, tannins, fat and starch are present. 

Clark-Lubs indicators. Phenol red, cresol red, bromophenol blue, bromocresol purple, thymol blue, bromthymol blue, and methyl red. 

Phenol red Bromthymol blue Rosolic acid Bromcresol purple Alizarine Bromcresol blue Bromphenol blue m-Cresol purple Thymol blue Methyl red Methyl orange Dimethyl yellow... 

Bromcresol green, Chlorphenol red. Methyl red, Bromcresol purple, Bromthymol blue, Phenol red, Neutral red, Cresol red, and Thymol blue (alkaline region). Acid solution in very dilute acetic acid (about 0.1 N) alkaline solution in dilute sodium carbonate (about 0.01 N-0.1 N). 

Indicator papers frequently aid in the identification of chemicals. Strong mineral acids are acid towards methyl violet or thymol blue papers, moderately strong acids react acid towards Congo paper, and very weak acids are acid towards htmus and azolitmin paper. Strong bases show an alkaline reaction with turmeric or tropeolin 0 paper, medium strong bases with phenol-phthalein, and very weak bases with litmus or azolitmin paper. These papers are not recommended for use in quantitative analysis. ... 

Figure 1. Diagrammatic representation of olfactory receptor cell activity during odour stimulation. The spot size is roughly proportional to spike frequency (spike/min). Receptor cells taken at random from the epithelium of a frog are identified hy a serial number in the left column (60 in all). ACE - acetophenone, ANI - anisole, BUT - n-butanol, CAM - DL-camphor, CDN - cyclodecanone, CIN - cineole, CYM, p-cymene, DCT D-citronellol, HEP - n-heptanol, ISO - isoamylacetate, IVA - isovaleric acid, LIM -D-linonene, MAC - methyl-amylketone, MEN - L-menthol, PHE - phenol, PHO -thiophenol, PYR - pyridine, THY - thymol, XOL - cyclohexanol, XON - cyclohexanone. (From Sicard Holley [7]).

Aromatics (menthol, thymol, eucalyptol, methyl salicylate, phenol). 

---