Toluene, 4-hydroxy

Aromatic substances, more than any other class of organic compounds, have acquired a large number of nonsystematic names. The use of such names is discouraged, but lUPAC rules allow for some of the more widely used ones to be retained (Table 15.1). rhus, methylbenzene is known commonly as toluene hydroxy benzene, as phenol aminobenzene, as aniline and so on. 

Similarly, 5-thiazole alkanoic acids and their salts are obtained from thioamides and /3-halo -y-keto acids (695). Thus thioarylamides condensed with 3-aroyl-3-bromopropionic acid (88) in isopropanolic solution in the presence of Na COs give first 4-hydroxy-2-aryl-A-2-thiazoline-5-acetic acid intermediates (89), which were dehydrated in toluene with catalytic amounts of p-toluene sulfonic acid to 2,4-diaryl-5-thiazole acetic acid (90) (Scheme 39) (657), with R = H or Me Ar = Ph, o-, m- or p-tolyl, o-, m-, or P-CIC6H4, 0-, m-, or p-MeOC(iH4, P-CF3C6H4, a-thienyl, a-naphthyl (657). 

Di-/ f2 -butyl-4-methylphenol, which is commonly known as BHT (butylated hydroxy toluene), is a widely used phenoHc antioxidant in the stabilization of oils, mbber, and polyolefins (44). BHT is also one of the few phenolic antioxidants approved by the FDA as a direct food additive where it is used to retard the oxidation of naturally occurring oils in food. 

Butadiene reacts readily with oxygen to form polymeric peroxides, which are not very soluble in Hquid butadiene and tend to setde at the bottom of the container because of their higher density. The peroxides are shock sensitive therefore it is imperative to exclude any source of oxygen from butadiene. Addition of antioxidants like /-butylcatechol (TBC) or butylated hydroxy toluene (BHT) removes free radicals that can cause rapid exothermic polymerizations. Butadiene shipments now routinely contain about 100 ppm TBC. Before use, the inhibitor can easily be removed (247,248). Inert gas, such as nitrogen, can also be used to blanket contained butadiene (249). 

A significant group of carbonamides are the Naphtol products formed by condensation of 2-hydroxy-3-naphthoic acid (via its acid chloride) with a wide range of arylamines. The simplest example, Naphtol AS from aniline, is typical, and manufacture is accompHshed by suspending the acid ia a solvent such as toluene, preforming the acid chloride by addition of phosphoms trichloride, and then adding the aniline. 

Anhydro-3-hydroxy-2-phenylthiazolo[2,3-6]thiazolylium hydroxide (407) underwent ready thermal reaction with alkynic and alkenic dipolarophiles in refluxing toluene. With the former dipolarophile sulfur was lost from the intermediate 1 1 cycloadduct (408) to give the substituted 5H-thiazolo[3,2- i]pyridin-5-ones (409). With the latter, the intermediate (410) lost H2S, also forming (409). 

Hydroxy-1,2,3,4-tetrahydrocrysene (2) A mixture of 4-keto-1,2 3 4-tetrahydrocrysene 1 (2 75 g, 11 mmol) and aluminium isopropoxide (8 2 g, 40 mmol) in PhMe (25 mL) was refluxed for 1 h After cooling, iPrOH (25 mL) was added and the formed acetone was distilled slowly maintaining the volume constant by addition of iPrOH After all acelone was distilled, the solution was acidified with 0% H2SO4 The separated toluene solution was evaporated to gwe 2 1 g of 2 (76%), mp 156-158 C... 

Some other inhibitors from the patent literature include hydroquinone [129], ionoP [130], and quinone [131]. Other inhibitors used to stabilize MMA include butylated hydroxy toluene (BHT), phenothiazine, methylene blue, hydroxy-diphenylamine and di-/jc/<3-napthol [132]. Several good reviews of inhibition and inhibitors have been written [133-136]. The mechanisms of inhibition are subtle and complicated. For example, it has been reported that highly purified benzo-quinone acts as a retarder rather than an inhibitor [137]. It has been proposed... 

The position of the free hydroxyl group in these two alkaloids is either C or C , since Spath has shown that the OiV-diacetyl derivative of -5-hydroxy-3 4-dimethoxyphenylethylamine, when heated in toluene solution with phosphoric oxide, yields a product which must be either 6-acetoxy-7 8-dimethoxy-, or 8-acetoxy-6 7-dimethoxy-l-methyl-3 4-dihydrowoquinoline. On reduction with tin and hydrochloric acid t is converted into anhalonidine, which must therefore be 6-hydroxy-7 8-dimethoxy- (or 8-hydroxy-6 7-dimethoxy-)-l-methyl-l 2 3 4-tetrahydrofsoquinoline. Similarly the methiodide of the acetoxy-com-pound on reduction yields, by loss of acetic acid and addition of two hydrogen atoms, pellotine, proving the latter to be A -methylanhalonidine. The position of the free hydroxyl group was finally shown by Spath to... 

This nitrite (5 g) is dissolved in 200 ml of toluene and photolyzed For 2 hr at 20° as described above. Without further treatment the solution is chromatographed on 100 g of alumina and eluted with methylene dichloride containing increasing proportions of methanol. The first fraction gives 0.6g prednisolone BMD. The latter fractions afford 17,20 20,21-bismethylenedioxy-llj5-hydroxy-18-oximinopregna-l,4-dien-3-one (3 g) mp 270-274° [oc]d 0°, after crystallization from ethyl acetate-hexane. 

In the preparation of C-nor-D-homosteroid hormone analogs Mitsuhashi and Harada extended the Bamford-Stevens rearrangement to the cholanic acid series. Treatment of 3a-hydroxy-12-oxocholanic acid /j-toluene-... 

Fusion of methyl or ethyl toluene- -sulfonates with 4-hydroxy-6-methyl-l,3,3a,7-tetraazaindene (135) gives only one salt, which on treatment with alkali is converted into a N-alkyl-4-oxo derivative. 

Fluorophenyl)-l ]-hydroxy-2,3,4,1 ]-tetrahydro-6/7-pyrimido[],2-Z)]-isoquinolin-6-one was obtained in the reaction of l-(4-fluorophenyl)-3-oxo-],3-dihydro-2-benzofuran-l-carboxamide and 1,3-diaminopropane in boiling toluene (01BMCL339). 

Vilsmeyer-Haack formylation of 7-hydroxy-2,3,6,7-tetrahydro-l//,5//-pyrido[3,2,l-y]quinazoline-l,3-dione with POCI3/DMF gave 7-chloro-6-formyl-2,3-dihydro-l//,5// derivative. Boiling a toluene solution of the aforementioned 7-hydroxy derivative in the presence of pTSA yielded dehydrated 2,3-dihydro derivative (01MI28). 

In further modifications of these norprogestins, reaction of norethindrone with acetic anhydride in the presence of p-toluene-sulfonic acid, followed by hydrolysis of the first-formed enol acetate, affords norethindrone acetate (41). This in turn affords, on reaction with excess cyclopentanol in the presence of phosphorus pentoxide, the 3-cyclopentyl enol ether (42) the progestational component of Riglovic . Reduction of norethindrone affords the 3,17-diol. The 33-hydroxy compound is the desired product since reactions at 3 do not show nearly the stereoselectivity of those at 17 by virtue of the relative lack of stereo-directing proximate substituents, the formation of the desired isomer is engendered by use of a bulky reducing agent, lithium aluminum-tri-t-butoxide. Acetylation of the 33,173-diol iffords ethynodiol diacetate, one of the most potent oral proves tins (44). ... 

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