Methods of making an alpha-olefin sulfonic dimer acid (AOS dimer acid) are disclosed. In one method, an alpha-olefin is sulfonated, preferably with sulfur trioxide, to produce a mixture comprising an alpha-olefin sulfonic acid (AOS acid) and sulfur dioxide. This mixture is then heated while purging sulfur dioxide and hydrogen sulfide from the reactor to produce an AOS dimer acid composition. In another method, the AOS acid mixture is treated to remove sulfur dioxide and is then heated to produce an AOS dimer acid composition. With either method, the resulting AOS dimer acid composition has at least a 30% decrease in the level of elemental sulfur when compared with that of an AOS dimer acid composition prepared by a similar process in the absence of any active removal of sulfur dioxide or hydrogen sulfide. AOS dimer acid compositions and salts of the AOS dimer acids, which are useful surfactants for oilfield and other applications, are also disclosed.

Methods of making an alpha-olefin sulfonic dimer acid (AOS dimer acid) are disclosed. In one method, an alpha-olefin is sulfonated, preferably with sulfur trioxide, to produce a mixture comprising an alpha-olefin sulfonic acid (AOS acid) and sulfur dioxide. This mixture is then heated while purging sulfur dioxide and hydrogen sulfide from the reactor to produce an AOS dimer acid composition. In another method, the AOS acid mixture is treated to remove sulfur dioxide and is then heated to produce an AOS dimer acid composition. With either method, the resulting AOS dimer acid composition has at least a 30% decrease in the level of elemental sulfur when compared with that of an AOS dimer acid composition prepared by a similar process in the absence of any active removal of sulfur dioxide or hydrogen sulfide. AOS dimer acid compositions and salts of the AOS dimer acids, which are useful surfactants for oilfield and other applications, are also disclosed.

Methods of making an alpha-olefin sulfonic dimer acid (AOS dimer acid) are disclosed. In one method, an alpha-olefin is sulfonated, preferably with sulfur trioxide, to produce a mixture comprising an alpha-olefin sulfonic acid (AOS acid) and sulfur dioxide. This mixture is then heated while purging sulfur dioxide and hydrogen sulfide from the reactor to produce an AOS dimer acid composition. In another method, the AOS acid mixture is treated to remove sulfur dioxide and is then heated to produce an AOS dimer acid composition. With either method, the resulting AOS dimer acid composition has at least a 30% decrease in the level of elemental sulfur when compared with that of an AOS dimer acid composition prepared by a similar process in the absence of any active removal of sulfur dioxide or hydrogen sulfide. AOS dimer acid compositions and salts of the AOS dimer acids, which are useful surfactants for oilfield and other applications, are also disclosed.

The invention relates to process for preparing an internal olefin sulfonate, comprising: a) sulfonating an internal olefin to produce a first sulfonated internal olefin mixture; and b) contacting the first sulfonated internal olefin mixture with water, caustic and a non-ionic surfactant to form a neutralized sulfonated internal olefin mixture wherein greater than 10 wt. % of the non-ionic surfactant is added.

The invention relates to process for preparing an internal olefin sulfonate, comprising: a) sulfonating an internal olefin to produce a first sulfonated internal olefin mixture; and b) contacting the first sulfonated internal olefin mixture with water, caustic and a non-ionic surfactant to form a neutralized sulfonated internal olefin mixture wherein greater than 10 wt. % of the non-ionic surfactant is added.

Presently provided are indoximod prodrug and salt compounds and pharmaceutical compositions comprising salts and prodrugs of indoximod, that produce enhanced plasma concentration and exposure to indoximod compared to direct administration of indoximod, in patients in need of treatment of immunosuppression mediated by the indoleamine-2,3-dioxygenase pathway, such as patients with cancer or chronic infectious diseases.

Presently provided are indoximod prodrug and salt compounds and pharmaceutical compositions comprising salts and prodrugs of indoximod, that produce enhanced plasma concentration and exposure to indoximod compared to direct administration of indoximod, in patients in need of treatment of immunosuppression mediated by the indoleamine-2,3-dioxygenase pathway, such as patients with cancer or chronic infectious diseases.

The present invention provides an internal olefin sulfonate composition, comprising water and an internal olefin sulfonate mixture having an average carbon number of at least 20, wherein the internal olefin sulfonate mixture comprises hydroxy sulfonates and alkene sulfonates in a weight ratio of hydroxy sulfonates to alkene sulfonates of at least 3.25. The invention further provides a method of treating a crude oil containing formation.

The present invention provides an internal olefin sulfonate composition, comprising water and an internal olefin sulfonate mixture having an average carbon number of at least 20, wherein the internal olefin sulfonate mixture comprises hydroxy sulfonates and alkene sulfonates in a weight ratio of hydroxy sulfonates to alkene sulfonates of at least 3.25. The invention further provides a method of treating a crude oil containing formation.

The present invention provides a sulfonium salt capable of providing a resist composition having few defects in photolithography where a high energy beam is used as a light source, and excellent in lithography performance by controlling acid diffusion.

The present invention was accomplished by a sulfonium salt including an anion and a cation, the cation having a partial structure represented by the following general formula (1), except for a sulfonium salt having a cation represented by the following general formula (1),

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