Hexa methyl benzene

RuO CjiHu, Ruthenium(II), (if-cyclopentadienyl) [2-[(diphenoxy-phosphino)oxy]phenyl-C, P] (triphen-ylphosphite-P)-, 26 178 RuPCji.Hjj, Ruthenium(II), [2-(diphenyl-phosphino)phenyl-C, P] (if-hexa-methyl-benzene)hydrido-, 26 182 Ru,C140,C24HJ4, Ruthenium(II), p-aqua-bis-(p.-chloroacetato)bis[(chloroacetato)... 

CnHie Penta-methyl benzene, etc. C12H18 Hexa-methyl benzene. C13H20 Heptyl benzene. 

It is found in nature as a mineral, in the form of an aluminium salt known as honey stone or mellite. It is formed when graphite is oxidized with nitric acid and it may be synthesized by oxidizing hexa-methyl benzene. 

But in this connection the reaction is in many cases, and indeed in the simplest case, not of equal importance with its application for the ketone syntheses, for three reasons First, the product of the reaction is a hydrocarbon which can again react thus it is often difficult to limit the reaction to the desired point- For example, in the action of methyl chloride on toluene, not only is one hydrogen atom substituted, with the formation of dimethyl benzene, but varying quantities of tri-, tetra-, penta-, and hexa-methyl benzene are also formed. A second disadvantage is this In the different series a mixture of isomers is obtained in the above case, e.g., not only one of the three dimethyl benzenes, but a mixture of the 0-, m-, and p-varieties is formed, which cannot be separated like the homologues by fractional distillation. The reaction is still further complicated in that the aluminium chloride partially splits off the alkyl groups ... 

In addition to the two methyl peaks near 5790 and 5735 cm, the methyl group in aromatic compounds has a band near 5660 cm, which has been found useful for quantitative analysis. Luty and Rohleder assigned this peak to be due to -i- 26. They also suggest that a peak at 4080 cm" is due to 38s, second overtone of a symmetric bending vibration of the CHj group. This peak is well isolated in compounds having multiple methyl groups such as penta and hexa-methyl benzene. 

Dimethyl 5,6-dihydro-2,3-dimethyl terephthalate Hexa methyl benzene Bi(cyclohex-l -enyl)... 

Methyl chloride (—) Aid, (0.3) 80 — Toluene, xylenes, trimethylbemsenes, durene, penta- and hexa-methyl-benzenes 164... 

The X-ray structures of benzene chromium tricarbonyl and of hexa-methyl benzene chromium tricarbonyl also suggest that the C—C bond distances are equivalent. In the hexamethylbenzene complex the methyl... 

When treated with lithium diisopropylamide, the unsubstituted simple bicyclic y-lactam, hexa-hydro-3//-pyrrolizin-3-one (1), furnishes the corresponding enolate which reacts with (halo-methyl)benzenes to give the a-alkylation products with rather poor diastereoselectivity10. The major product 2 has cis configuration. Equilibration of the product with base gives a 72 28 mixture in favor of the frans-diastereomer10. 

H0.H2C.C=C(CHs0H)- (CH20H) HO.H2C.C=C(CH2OH)-C(CH2OH). This compd, prepd by Backer(Ref 2) and called Hexahydroxy-methyl-benzene, is a parent compd of its hexa-nitrate... 

CYCLOHEXENONE. A remarkable large-scale preparation of a Dewar benzene derivative is illustrated by the preparation of HEXA-METHYL DEWAR BENZENE from dimethylacetylene. 

Syntheses of the parent [6]radialene (5) were published by three research groups in 1977/1978 4, 5, 6. Among the various gas-phase flash pyrolysis reactions reported, the triple HCl-elimination from l,3,5-tris(chloromethyl)mesitylene (109) is the most practicable one and yields the radialene in 35 -48% yield (Scheme 4.23) [5] other flash pyrolyses were carried out, typically at 900 °C, with cyclododeca-l,5,9-triyne, benzo[l,2 4,5]dicyclobutene derivatives and benzo[l,2-c 3,4-c 5,6-c"]tris(2,5-dihydrothiophene 1,1-dioxide). The sixfold dehydrobromination of hexa(bromomethyl)benzene (110) with methyl lithium at low temperature has been achieved more recently in this case, 5 has been trapped without isolation by cyclopropanation reactions yielding spiro compounds 111 in very low yield [88]. Radialene 5 is a diSicult-to-handle, extremely air-sensitive compound with properties [5] that resemble those described for the parent radialenes 2 and 3 see Sections 4.2.1 and 4.2.2. 

The structural comparison (Fig. 3) with both the twofold tris(trimethylsilyl)methyl substituted acetylene and 1,4-benzene derivatives (Fig. 1) as well as with the literature data [6a] for hexa-kis(rm.butyl)disilane [6b] containing a SiSi bond elongated to 270 pm ( ), for the linear ( ) hexa-kis(rm.butyl)disiloxane [6c] or for di(tris(trimethylsilyl)silyl)zinc [6d] is based advantageously on a model in which the two substituent half-shells are separated along their central C3 axes by spacers of different lengths. 

Solvents and reagents are dried in the following fashion Benzene and ether are freshly distilled from sodium methyl iodide is distilled over calcium chloride and potassium hexa-chloroplatinate(IV) is dried at 110°. 

Benzene-l,4-diols are oxidized to quinones by benzyltrimethylammonium tribromide under mild conditions in almost quantitative yields [6]. With an excess of the tribromide further reaction produces the 2-bromo-l, 4-quinones. This oxidation is in contrast to the analogous reaction of phenols, which produces bromophenols (see Section 2.3). Hindered 4-methyl-phenols are oxidized to the corresponding benzyl alcohols, benzaldehydes, bromomethyl derivatives and 4-bromo-4-methylcyclo-hexa-2,5-dien-l-ones [7]. Benzylic alcohols are oxidized under neutral or basic conditions to yield the corresponding aldehydes (>70%) oxidation with an excess of the reagent produces the benzoic acids (>90%) [8],... 

Temper- ature °C Chloro- form Methyl acetate Ethyl acetate Cyclo- hexa- none Nitro- benzene Pyridine Mesityl oxide... 

Thermal decomposition of 1-butene provides a more complex product spectrum than is obtained from either cis- or trans-2-butenes. Between 550° and 760°C in a flow system with nitrogen dilution (3), methane, propylene, butadiene, and ethylene were major products as well as hydrogen, ethane, 1-pentene, 2-pentene, 3-methyl-1-butene, and 1,5-hexa-diene. In studies in a static system (4), cyclohexadienes, benzene, cyclopentene, cyclopentadiene, toluene, orthoxylene, and cyclohexene were observed among the liquid products of the reaction over the temperature range 490°-560°C. 

Di-amino derivatives of the secondary amines, mono-methyl aniline, and the tertiary amines, di-methyl aniline, are also known. Of these compounds the para-amino di-methyl aniline is the most important in the dyestuff industry. Tri-amino, tetra-amino, penta-amino and hexa-amino derivatives of benzene and also penta-amino toluene are all known. 

Reduction of 3-methyl-1,2-diphenylcyclopropenylium perchlorate (24) with a slurry of activated magnesium metal in diethyl ether afforded the hexasubstituted benzenes 25 and 26 together with derivatives of bi(cyclopropenyl) 27 and bicyclo[2.2.0]hexa-2,5-diene 28. ... 

Diels-Alder dienes Benzene, see Dicyanoacetylene. Cyclooctatetraene, see 4-Phenyl-l,2,4-triazoline-3,5-dione. Cyclopentadiene ketals. cis-7,8-Dichlorobicyclo[4.2.0]octadiene-2,4, see cis-3,4-Dichlorocyclobutene. 5,5-Dimethoxy-l,2,3,4-tetrachlorocyclopentadiene. Hexa-chlorocyclopentadiene. Methyl tra .rl2,4-pentadienoate. A 4 l6-Steroid dienes, see 4-Phenyl-l,2,4-triazoline-3,5-dione. Tetrachlorocyclopentadienone ethylene ketal ... 

FIGURE 18. He(I) spectra of (A) 2,3,5,6-tetrakis(trimethylsilylmethyl)benzene, (B) extended records 6.5 eV to 9.5 eV for 1,4-, 2,6-, 1,3,5- and hexa-substituted derivatives and (C) comparison of ionization energies IE1 2 with those of the corresponding methyl-substituted benzenes126... 

Dewar pyridine, 2-azabicyclo[2.2.0]hexa-2,5-diene (218), thermally reverted to pyridine at room temperature with a half-life time of 2.5 minutes (Ea = 16 kcal/mol).255 Far more stable were 2-azabicyclo-[2.2.0]hex-5-en-3-ones (225).265-267 The kinetics of the thermal (2 + 2)-cycloreversion of 225 (R = Me) in the temperature range of 130° to 160° have been reported (A//J = 33.2 kcal mol-1 ASt = + 2.7 cal mol-1 deg-1).266 An interesting difference in rate was observed between 225 (R = H) and its methyl homolog 225 (R = Me). At 130° the former reverted ten times as rapidly to 2-pyridone as the latter did to 1-methyl-2-pyridone this difference has been related to the intermediacy of the lactim tautomer of 225 (R = H) in the former reaction. Dewar benzene oxide, 2,3-epoxybicyclo[2.2.0]hex-5-ene (266), isomerized to an equilibrium mixture of benzene oxide/oxepin at 115° with a half-life time of 18 minutes.270 The relatively high thermal stability of such strained bicyclic heterocycles has been attributed to the fact that the symmetry-allowed conrotatory process would give rise to an unfavored cis.trans heterocyclic diene.265... 

The AIBN-initiated cycloaddition of hexa-l,5-diyne with phenylarsine in boiling benzene for 7 h affords 1-phenyl-4,5-dihydroarsepin (13) (b.p. 68-70°C/0.01 mm Hg) (Scheme 2). The compound was characterized by IR, MS, and H NMR spectroscopy, and by quaternization with methyl iodide and benzyl bromide, which gave the respective arsonium salts (14 R = Me or Bn X = I or Br)... 

Representative procedure [11] a round-bottomed flask was charged with 8mL morpholine (30 mmol) and dimethylacetamide dimethyl acetal (3.8 mL, 10mmol) and the mixture was slowly heated to 190 °C over 5 h under a steady stream of N2. After cooling to room temperature, dry benzene (10 mb) and 3-methyl-but-3-en-2-ol 11 (430 mg, 5 mmol) were added. The reaction mixture was transferred to a sealed tube and the solution was refluxed until the allylic alcohol was consumed (24 h) as determined by TLC (30% hexanes in ethyl acetate, v/v). The solvent was removed in vacuo and the residue was purified by column chromatography (hexa-nes ethyl acetate 2 1—> 1 1) to afford the pure product 12 as a colorless oil (870 mg, 4.5 mmol, 90%). 

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