Hexa ethyl benzene

The corresponding data for ethylbenzenes are not available, but a comparison with the ethylborazoles indicates that negative deviations might be expected for tetra-, penta- and hexa-ethyl-benzenes,... 

The reaction was extended to PhCH2X (X = Cl or Br) which gives the hexa(phenyl-ethyl)benzene complex. The new free aromatic ligand is easily disengaged by photolysis in acetonitrile [76a] Eq. (20). This line of research is now offering us the perspective of making new discotic liquid crystals using suitably substituted... 

Treatment of ethyl 1 W-azepine-l-carboxylate with palladium(II) acetate in benzene, or in an aprotic solvent, results in ring contraction (see Section 3.1.2.4.) or ring opening (vide infra), respectively, however, with palladium(II) acetate in acetic acid ethyl 2,3-diacetoxy-2,3-dihydro-l//-azepine-l-carboxylate (6) is formed as the major product along with ( , )-hexa-2,4-dienedial.243... 

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

Kinetic reaction rate constants increase with the number of ethyl groups alkylated on the benzene ring. For example, the relative rate constant for alkylation of EB is roughly twice that for the alkylation of benzene. Reaction rate constants continue to increase with each successive alkylation reaction until a limitation is reached, such as steric hindrance. The formation of penta-EB and hexa-EB proceeds very slowly for this and other reasons so that only trace quantities are formed. 

Though it requires vigorous conditions and is less common than nucleophilic epoxidation, electrophilic epoxidation of aperfluoroalkene is possible with the potent combination of chromic oxide and fluorosulfonic acid, providing another route to hexafluoropropylene oxide (1). As a further example of electrophilic attack, hexa-fluoro Dewar benzene (3) is transformed into either a mono- or a diepoxide by the powerful hypofluorous acid-acetonitrile complex.The fact that the much weaker electrophile MCPBA readily epoxides such electron-deficient alkenes as ethyl pentafiuoromethacrylate (4) suggests that it actually reacts via nucleophilic attack at the [3-carbon. 

Commencing with alkyl group rotations, there have been two studies of the stereodynamics of chromium carbonyl complexes with 77 -hexaalkylbenzene. For the complex [ Cr(CO)2L 2(/i-N2)] (L = ry -hexaethylbenzene), NMR band-shape changes were attributed to slowed ethyl group rotation with a barrier, AG (300 K), of 46.0 3.0 kJ moP. The ligand hexa-n-propyl-benzene adopts a D3d symmetry with the alkyl substituent alternately up and down with respect to the observer. This geometry is retained in the chromium tricarbonyl complex and a decoalescence phenomenon observed in its NMR spectrum was... 

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%). 

Solvent system Benzene-ethyl acetate-methanol (85 13.5 1.5). Proto-, copro-, and uroporphyrin are commercial (Sigma). Penta-, hexa-, and heptaporphyrin are isolated from human porphyric urine. Substituent position refers to free pigments in Fig. 17, and the abbreviations are as follows Me = -CHj, V = -CH = CHi, Ac = -CH2COOH, and Pr = -CH2CH2COOH. 

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