Abstract: A continuous process for the preparation of 2-hydroxy-4-methylthiobutanoic acid which includes introducing sulfuric acid into a first reactor including a continuous stirred tank reactor and introducing 2-hydroxy-4-methylthiobutanenitrile into the first reactor. 2-hydroxy-4-methylthiobutanenitrile is continually hydrolyzed within the first reactor to produce an intermediate aqueous hydrolysis solution containing 2-hydroxy-4-methylthiobutanamide. The intermediate aqueous hydrolysis solution is continuously introduced into a plug flow reactor. 2-hydroxy-4-methylthiobutanamide is continually hydrolyzed within the plug flow reactor to produce an aqueous hydrolyzate product solution containing 2-hydroxy-4-methylthiobutanoic acid. 2-hydroxy-4-methylthiobutanoic acid is recovered from the aqueous hydrolyzate product solution.

Abstract: A continuous process for the preparation of 2-hydroxy-4-methylthiobutanoic acid or a salt thereof which includes introducing an aqueous mineral acid into a nitrile hydrolysis reactor including a continuous stirred tank reactor and introducing 2-hydroxy-4-methylthiobutanenitrile into the nitrile hydrolysis reactor. 2-hydroxy-4-methylthiobutanenitrile is continually hydrolyzed within the nitrile hydrolysis reactor to produce a nitrile hydrolysis reactor product stream containing 2-hydroxy-4-methylthiobutanamide. The nitrile hydrolysis reactor product stream is continuously introduced into an amide hydrolysis flow reactor. 2-hydroxy-4-methylthiobutanamide is continually hydrolyzed within the amide hydrolysis flow reactor to produce an aqueous hydrolyzate product containing 2-hydroxy-4-methylthiobutanoic acid. 2-hydroxy-4-methylthiobutanoic acid is recovered from the aqueous hydrolyzate product.

Abstract: A continuous process for the preparation of 2-hydroxy-4-methylthiobutanoic acid which includes introducing sulfuric acid into a first reactor including a continuous stirred tank reactor and introducing 2-hydroxy-4-methylthiobutanenitrile into the first reactor. 2-hydroxy-4-methylthiobutanenitrile is continually hydrolyzed within the first reactor to produce an intermediate aqueous hydrolysis solution containing 2-hydroxy-4-methylthiobutanamide. The intermediate aqueous hydrolysis solution is continuously introduced into a plug flow reactor. 2-hydroxy-4-methylthiobutanamide is continually hydrolyzed within the plug flow reactor to produce an aqueous hydrolyzate product solution containing 2-hydroxy-4-methylthiobutanoic acid. 2-hydroxy-4-methylthiobutanoic acid is recovered from the aqueous hydrolyzate product solution.

Abstract: A continuous process for the preparation of 2-hydroxy-4-methylthiobutanoic acid or a salt thereof which includes introducing an aqueous mineral acid into a nitrile hydrolysis reactor including a continuous stirred tank reactor and introducing 2-hydroxy-4-methylthiobutanenitrile into the nitrile hydrolysis reactor. 2-hydroxy-4-methylthiobutanenitrile is continually hydrolyzed within the nitrile hydrolysis reactor to produce a nitrile hydrolysis reactor product stream containing 2-hydroxy-4-methylthiobutanamide. The nitrile hydrolysis reactor product stream is continuously introduced into an amide hydrolysis flow reactor. 2-hydroxy-4-methylthiobutanamide is continually hydrolyzed within the amide hydrolysis flow reactor to produce an aqueous hydrolyzate product containing 2-hydroxy-4-methylthiobutanoic acid. 2-hydroxy-4-methylthiobutanoic acid is recovered from the aqueous hydrolyzate product.

Abstract: A continuous process for the preparation of 2-hydroxy-4-methylthiobutanoic acid which includes introducing sulfuric acid into a first reactor including a continuous stirred tank reactor and introducing 2-hydroxy-4-methylthiobutanenitrile into the first reactor. 2-hydroxy-4-methylthiobutanenitrile is continually hydrolyzed within the first reactor to produce an intermediate aqueous hydrolysis solution containing 2-hydroxy-4-methylthiobutanamide. The intermediate aqueous hydrolysis solution is continuously introduced into a plug flow reactor. 2-hydroxy-4-methylthiobutanamide is continually hydrolyzed within the plug flow reactor to produce an aqueous hydrolyzate product solution containing 2-hydroxy-4-methylthiobutanoic acid. 2-hydroxy-4-methylthiobutanoic acid is recovered from the aqueous hydrolyzate product solution.

Abstract: A continuous process for the preparation of 2-hydroxy-4-methylthiobutanoic acid or a salt thereof which includes introducing an aqueous mineral acid into a nitrile hydrolysis reactor including a continuous stirred tank reactor and introducing 2-hydroxy-4-methylthiobutanenitrile into the nitrile hydrolysis reactor. 2-hydroxy-4-methylthiobutanenitrile is continually hydrolyzed within the nitrile hydrolysis reactor to produce a nitrile hydrolysis reactor product stream containing 2-hydroxy-4-methylthiobutanamide. The nitrile hydrolysis reactor product stream is continuously introduced into an amide hydrolysis flow reactor. 2-hydroxy-4-methylthiobutanamide is continually hydrolyzed within the amide hydrolysis flow reactor to produce an aqueous hydrolyzate product containing 2-hydroxy-4-methylthiobutanoic acid. 2-hydroxy-4-methylthiobutanoic acid is recovered from the aqueous hydrolyzate product.

Abstract: A continuous process for the preparation of 2-hydroxy-4-methylthiobutanoic acid which includes introducing sulfuric acid into a first reactor including a continuous stirred tank reactor and introducing 2-hydroxy-4-methylthiobutanenitrile into the first reactor. 2-hydroxy-4-methylthiobutanenitrile is continually hydrolyzed within the first reactor to produce an intermediate aqueous hydrolysis solution containing 2-hydroxy-4-methylthiobutanamide. The intermediate aqueous hydrolysis solution is continuously introduced into a plug flow reactor. 2-hydroxy-4-methylthiobutanamide is continually hydrolyzed within the plug flow reactor to produce an aqueous hydrolyzate product solution containing 2-hydroxy-4-methylthiobutanoic acid. 2-hydroxy-4-methylthiobutanoic acid is recovered from the aqueous hydrolyzate product solution.

Abstract: A continuous process for the preparation of 2-hydroxy-4-methylthiobutanoic acid which includes introducing sulfuric acid into a first reactor including a continuous stirred tank reactor and introducing 2-hydroxy-4-methylthiobutanenitrile into the first reactor. 2-hydroxy-4-methylthiobutanenitrile is continually hydrolyzed within the first reactor to produce an intermediate aqueous hydrolysis solution containing 2-hydroxy-4-methylthiobutanamide. The intermediate aqueous hydrolysis solution is continuously introduced into a plug flow reactor. 2-hydroxy-4-methylthiobutanamide is continually hydrolyzed within the plug flow reactor to produce an aqueous hydrolyzate product solution containing 2-hydroxy-4-methylthiobutanoic acid. 2-hydroxy-4-methylthiobutanoic acid is recovered from the aqueous hydrolyzate product solution.

Abstract: A continuous process for the preparation of 2-hydroxy-4-methylthiobutanoic acid or a salt thereof which includes introducing an aqueous mineral acid into a nitrile hydrolysis reactor including a continuous stirred tank reactor and introducing 2-hydroxy-4-methylthiobutanenitrile into the nitrile hydrolysis reactor. 2-hydroxy-4-methylthiobutanenitrile is continually hydrolyzed within the nitrile hydrolysis reactor to produce a nitrile hydrolysis reactor product stream containing 2-hydroxy-4-methylthiobutanamide. The nitrile hydrolysis reactor product stream is continuously introduced into an amide hydrolysis flow reactor. 2-hydroxy-4-methylthiobutanamide is continually hydrolyzed within the amide hydrolysis flow reactor to produce an aqueous hydrolyzate product containing 2-hydroxy-4-methylthiobutanoic acid. 2-hydroxy-4-methylthiobutanoic acid is recovered from the aqueous hydrolyzate product.

Abstract: Described herein is a catalytic processes for the preparation of 3-(methylthio)propanal and 2-hydroxy-4-(methylthio)butanenitrile using novel addition catalysts are disclosed. The novel addition catalysts include:triisopropanolamine, nicotinamide, imidazole, benzimidazole, 2-fluoropyridine, poly-4-vinylpyridine, 4-dimethylaminopyridine, picoline, pyrazine, trialkylamines having from three to eighteen carbon atoms in each of the alkyl substituents bonded to the nitrogen atom and tertiary amines having the formula ##STR1## wherein A is aryl, R.sub.1 and R.sub.2 are alkyl and x, a, b and c are integers such that 0.ltoreq.x.ltoreq.3, 1.ltoreq.a.ltoreq.3, 0.ltoreq.b.ltoreq.2, 0.ltoreq.c.ltoreq.2 provided that a+b+c=3.

Abstract: Catalytic processes for the preparation of 3-(methylthio)propanal and 2-hydroxy-4-(methylthio)butanenitrile using novel addition catalysts are disclosed. The novel addition catalysts include: nicotinamide, imidazole, benzimidazole, 2-fluoropyridine, poly-4-vinylpyridine, 4-dimethylaminopyridine, picoline and pyrazine.