There is disclosed a process for producing taurine from ammonium isethionate by the ammonolysis of alkali isethionate in the presence of alkali ditaurinate or alkali tritaurinate, or their mixture, to inhibit the formation of byproducts and to continuously convert the byproducts of the ammonolysis reaction to alkali taurinate. Alkali taurinate is reacted with ammonium isethionate to obtain taurine and to regenerate alkali isethionate. The production yield is increased to from 90% to nearly quantitative. The ammonolysis reaction is catalyzed by alkali salts of hydroxide, sulfate, sulfite, phosphate, or carbonate.

There is disclosed a process for producing taurine from ammonium isethionate by the ammonolysis of alkali isethionate in the presence of alkali ditaurinate or alkali tritaurinate, or their mixture, to inhibit the formation of byproducts and to continuously convert the byproducts of the ammonolysis reaction to alkali taurinate. Alkali taurinate is reacted with ammonium isethionate to obtain taurine and to regenerate alkali isethionate. The production yield is increased to from 90% to nearly quantitative. The ammonolysis reaction is catalyzed by alkali salts of hydroxide, sulfate, sulfite, phosphate, or carbonate.

A salt having a group represented by formula (a): ##STR00001## wherein X.sup.a and X.sup.b each independently represent an oxygen atom or a sulfur atom, X.sup.1 represents a divalent group having an alicyclic hydrocarbon group where a methylene group may be replaced by an oxygen atom or a carbonyl group, and where a hydrogen atom may be replaced by a hydroxy group or a fluorine atom, and * represents a binding site.

A salt having a group represented by formula (a): ##STR00001## wherein X.sup.a and X.sup.b each independently represent an oxygen atom or a sulfur atom, X.sup.1 represents a divalent group having an alicyclic hydrocarbon group where a methylene group may be replaced by an oxygen atom or a carbonyl group, and where a hydrogen atom may be replaced by a hydroxy group or a fluorine atom, and * represents a binding site.

The present invention discloses a fluorescent probe for detecting a sulfenated protein, which has good stability and can specifically quantitatively detect a sulfenated protein in complex biological samples, and has a good detection ability of signal-to-noise ratios, is highly sensitive, and has excellent selectivity, thereby realizing specific detection of sulfhydryl sulfenation modification of intracellular proteins.

The present invention discloses a fluorescent probe for detecting a sulfenated protein, which has good stability and can specifically quantitatively detect a sulfenated protein in complex biological samples, and has a good detection ability of signal-to-noise ratios, is highly sensitive, and has excellent selectivity, thereby realizing specific detection of sulfhydryl sulfenation modification of intracellular proteins.

A radiation-sensitive composition includes: a first polymer having a first structural unit that includes an acid-labile group; and a first compound including a metal cation and a first anion that is a conjugate base of an acid. The acid has a pKa of no greater than 0. The acid is preferably sulfonic acid, nitric acid, organic azinic acid, disulfonylimidic acid or a combination thereof. The first compound is preferably represented by formula (1). In the formula (1), M represents a metal cation; A represents the first anion; x is an integer of 1 to 6; R.sup.1 represents a σ ligand; and y is an integer of 0 to 5, and a sum: x+y is no greater than 6. The van der Waals volume of the acid is preferably no less than 2.5×10.sup.−28 m.sup.3.
[A.sub.xMR.sup.1.sub.y]  (1)

A radiation-sensitive composition includes: a first polymer having a first structural unit that includes an acid-labile group; and a first compound including a metal cation and a first anion that is a conjugate base of an acid. The acid has a pKa of no greater than 0. The acid is preferably sulfonic acid, nitric acid, organic azinic acid, disulfonylimidic acid or a combination thereof. The first compound is preferably represented by formula (1). In the formula (1), M represents a metal cation; A represents the first anion; x is an integer of 1 to 6; R.sup.1 represents a σ ligand; and y is an integer of 0 to 5, and a sum: x+y is no greater than 6. The van der Waals volume of the acid is preferably no less than 2.5×10.sup.−28 m.sup.3.
[A.sub.xMR.sup.1.sub.y]  (1)

A salt represented by formula (I), a generator and a resist composition:

##STR00001##

wherein R.sup.1 and R.sup.2 each independently represent an iodine atom, a fluorine atom or an alkyl fluoride group having 1 to 6 carbon atoms; R.sup.4, R.sup.5, R.sup.7 and R.sup.8 each independently represent a halogen atom, a hydroxy group, a haloalkyl group having 1 to 12 carbon atoms or an alkyl group having 1 to 12 carbon atoms, —CH.sub.2— included in the haloalkyl group and the alkyl group may be replaced by —O—, —CO—, —S— or —SO.sub.2−; X.sup.1 and X.sup.2 each independently represent an oxygen atom or a sulfur atom; m1 represents 1 to 5, m2 and m8 represent 0 to 5, and m4, m5 and m7 represent an integer of 0 to 4, in which 1≤m1+m7≤5, 0≤m2+m8≤5; and AI.sup.− represents an organic anion.

Provided herein are improved processes and methods for preparing osimertinib or a salt thereof, in particular osimertinib mesylate. The improved process removes the necessity of isolating the unstable aniline intermediate of formula (III) and enables the direct coupling to form the amide product of formula (II):

##STR00001##

The present invention is suitable for a large-scale production, avoiding the isolation of unstable intermediate, thereby providing osimertinib or a mesylate salt thereof in both high yields and high purity.