Sulfolane as solvent

Whatever the solvent and the zeolite, large differences can be observed between the compositions of RM and AM mixtures and this behaviour confirms that organic molecules compete for adsorption within the zeolite micropores. Sulfolane, a very polar solvent, is more strongly adsorbed than 2-MN whereas the less polar nitrobenzene solvent is less strongly adsorbed (Table 2.2). This explains the lower rate of 2-MN acetylation with A A found with sulfolane as solvent.1591 AMN, the products of this acetylation, are more strongly adsorbed than 2-MN which suggests an autoinhibited process. 

Data in parentheses refer to tests carried out in sulfolane as solvent. 

The Newman-Kuart rearrangement is an example of a high-temperature reaction [34]. With the use of a microreactor, the reaction temperature could be extended up to 200 °C. 0-(2-Nitrophenyl)-N,N-dimethylthiocarbamate was converted to S-(2-nitro-phenyl)-N,N-dimethylcarbamothioate at 170 °C in 14 min at 90% yield. Quantitative conversion with a throughput of 34 g/h was achieved with sulfolane as solvent at the same temperature and reaction time. 

The behavior of acyl manganese pentacarbonyls toward CO-H2 mixtures has been studied . With sulfolane as solvent, at 75°C, PhCH2C(0)Mn(C0)5 forms the corresponding aldehyde ... 

In contrast, the use of sulfolane as solvent allows a conversion of benzene close to 8% while maintaining the selectivity to phenol higher than 80%. Detected byproducts are catechol (7%), hydroquinone (4%), 1,4-benzoquinone (1%) and tars (5%) [19]. 

In this case, the conversion of cyclododecanone and cyclooctanone oxime were done by the Beckman rearrangement in liquid phase, in a batch reactor at 403 and 433 K, respectively, with a catalyst to oxime ratio of 1 2 wt.wf, and chlorobenzene and sulfolane as solvent, respectively. The results reported in Table 5 show a higher activity for the delaminated ITQ-2 sample. Moreover, adsorbed products are easier to be removed from the surface of the delaminated material, as indicated by the smaller amount of organic left on the solid after reaction which was in the case of cyclododecanone-oxime, 2, 3 and 5 wt% for ITQ-2, MCM-41 and Beta, respectively. By optimising temperature and solvent, conversions higher than 95% with selectivities to the lactames > 98% can be obtained with ITQ-2. 

Significant differences in the acetylation of naphthalene with acetic anhydride (2 1 molar ratio) over HBEA are observed with decalin or sulfolane as solvents the diffoent hydrophilicities of these solvents dramatically inflnence the resulting naphthalene conversion. The hydrophilic sulfolane into-acts more strongly with the zeolite surface, thus blocking the acid sites that are less available for the acylation reaction (naphthalene conversion = 14%) on the contrary, the hydrophobic decalin enables the adsorption of acetic anhydride and increases the rate of acylation reaction (naphthalene conversion=25%). Due to the defined structure of the HBEA, the selective formation of isoma-15 is probably achieved via a restricted transition state selectivity (15 13=81 19 at 35% naphthalene conversion). It must be underlined that different secondary products are, in general, produced on the catalyst surface due to consecutive reaction of the products. 

It may be not so easy to develop such pigments, but blue pigments with a more reddish shade may be affected by consideration of crystal forms, substituents, and central metal ions. It has been found that copper phthalocyanine, synthesized from a mixture of phthalic anhydride and a small portion of trimellitic anhydride and pyr-omellitic anhydride in sulfolane as solvent under pressure, exhibits the pi form, with a more reddish shade than that of epsilon copper phthalocyanine. ... 

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