P-Cresyl methyl ether

Fora (4-Methyl anisole, p-Cresyl methyl ether, p-Methoxy toluene or Methyl-p-Cresol), colorl... 

Ylang-ylang Cananga odorata Hook, f et Thoms. Benzyl acetate (6-18), geranyl acetate (3-14), p-cresyl methyl ether (15-16), methyl benzoate (4-9)... 

Phenyl n-propyl et.her. Phenyl n-butyl ether o-Cresyl methyl ether (1) m-Cresyl methyl ether. p-Cresyl methyl ether. o-Cresyl ethyl ether m-Cresyl ethyl ether p-Cresyl ethyl ether Benzyl methyl ether Benzyl ethyl ether Methyl a-naphthyl ether Methyl p-naphthyl ether Ethyl a-naphthyl ether Ethyl p-naphthyl ether Benzyl a-naphthyl ether Benzyl P-naphthyl ether o-Methoxydiphenyl p-Methoxydiphenyl. o-Chloroanisole. m-Chloroanisole. p-Chloroanisolc o-Bromoanisole m-Bromoanisole. p-Bromoanisole. o-Iodoanisole m-Iodoanisole p-Iodoanisole o-Nitroanisole... 

General conditions for the oxidation of an alkyl side chain attached to an aromatic ring are given under Aromatic hydrocarbons, Section 9.6.3, p. 1239. The following procedure for the oxidation of p-cresyl methyl ether to anisic acid is illustrative. 

Prepare a solution of 6 g of potassium permanganate in a mixture of 20 ml of 5 per cent sodium hydroxide solution and 150 ml of water, add 2.0 g of p-cresyl methyl ether and heat under reflux for 2-3 hours. If any permanganate remains at the end of this period, destroy it by the addition of a few drops of ethanol. Remove the precipitated manganese dioxide by filtration at the pump, evaporate the filtrate to a volume of 25-30 ml and acidify it (to Congo red) with dilute sulphuric acid. Anisic acid, m.p. 183-184°C, crystallises out on cooling. 

Generally, the extra grades will have more benzyl acetate and p-cresyl methyl ether, a high proportion of linalool and a lower proportion of sesquiterpenes when compared to lower grades. The lower grades have increased sesquiterpenes, with a resultant harsher oily character. Table 7.5 shows typical published data for compositions of the various grades. 

FEMA No. 2681 p-Cresyl Methyl Ether Methyl p-Cresol... 

Cresol Red-Thymol Blue TS, 851 Cresol Red TS, 851 o-Cresolsulfonphthalein, 860 p-Cresyl Acetate, 474, 568, 684, (S 1)66 p-Cresyl Isobutyrate, 558 p-Cresyl Methyl Ether, 524 Criteria for Food Chemicals Codex Grade, xx... 

SYNS p-CRESOL methyl ether p-cresyl METHYL ETHER FEMANo. 2681 p-METHOXY-TOLUENE 4-METHOXYTOLUENE 4-METHYL-l-METHOXYBENZENE 4-METHYLPHENOL METHYL ETHER METHYL-p-TOLYL ETHER p-TOLYL METHYL ETHER... 

For some of the cresol derivatives such as p-anisic aldehyde based on oxidation of p-cresyl-methyl ether (PCME) using 80-82% Mn02 and sulfuric acid (80%) good quantities of spent MnSO4 along with excess acid are invariably produced and the waste streams have to be neutralized and solid Mn-sulfate has to be recovered towards waste minimization. 

This is the most important inorganic by-product formed during production of p-anisic aldehyde from p-cresol via the intermediate product p-cresyl-methyl ether (PCME). Manganese dioxide Mn02 (80-82%) in presence of sulfuric acid (80%) converts PCME to p-anisic aldehyde and a by-product stream rich in manganese sulfate and excess spent sulfuric acid used in the oxidation reaction as shown below ... 

As in the case of many fine chemicals, waste minimization in the liquid streams is a must in the field of cresols and allied products. Many plants producing cresols from coal carhonization process have been closed down because of inherent problems of production of waste materials and byproducts. Same is the story with producers of p-anisic aldehyde using Mn02 as the catalyst. Some manufacturers found it economically not viable to recover both sodium sulfate and manganese sulfate from the waste streams involving etherification of para-cresol and oxidation of p-cresyl methyl ether. These plants were eventually closed down which has been discussed adequately in earlier chapters. 

CsHgC, Mr 136.15, pi.85kPa 132 °C, df 1.1192, n 1.5703, occurs in many essential oils, often together with anethole. It is a colorless to slightly yellowish liquid with a sweet, mimosa, hawthorn odor. p-Anisaldehyde can be hydrogenated to anise alcohol and readily oxidizes to anisic acid when exposed to air. Synthetic routes to anisaldehyde start from p-cresyl methyl ether, which is oxidized e.g. by manganese dioxide or by oxygen or peroxy compounds in the presence of transition metal catalysts [170], [171]. 

The compositions of the various oil fractions depend on the duration of distillation. The first fraction, ylang-ylang oil Extra, has the highest content of strongly odoriferous constituents such as p-cresyl methyl ether (5-16%), methyl benzoate... 

Synonyms p-Cresol methyl ether p-Cresyl methyl ether Methoxy-1 methyl-4 benzene 1-Methoxy-4-methylbenzene 4-Methoxytoluene p-Methoxytoluene 4-Methylanisole Methyl p-cresol 4-Methyl-1-methoxybenzene 4-Methylphenol methyl ether Methyl-p-tolyl ether p-Tolyl methyl ether Classification Aromatic ether Empirical CsHioO... 

Geranial, neral a-vetivone, -vetivone, khusimol, isovalencenol Benzyl acetate, geranyl acetate, p-cresyl methyl ether, methyl henzoate... 

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