Process for preparing the compound 5-t-butyl-2-methylamino-1,3,4-triadiazole
AssigneeMorton-Norwich Products, Inc.
InventorsDavid L. Booth, Richard M. Rodebaugh
Life of this patent
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Abstract
A process for preparing the compound 5-t-butyl-2-methylamino-1,3,4-thiadiazole, ##STR1## in high yield by the reaction of 4-methyl-3-thiosemicarbazide with pivalic acid in a solution containing both polyphosphoric acid and concentrated sulfuric acid, followed by neutralizing the reaction mixture with a neutralizing mixture comprising an organic solvent and an alkaline substance dissolved in water and separating 5-t-butyl-2-methylamino-1,3,4-thiadiazole from the organic phase.
Claims25
A process for preparing the compound 5-t-butyl-2-methylamino-1,3,4-thiadiazole in high yield comprising:
- (i) adding 4-methyl-3-thiosemicarbazide to a solution of pivalic acid to form a slurry in a first vessel;
- (ii) placing a solution comprising polyphosphoric acid and concentrated sulfuric acid in a second vessel;
- (iii) feeding the contents of said first and second vessels concomitantly into a third vessel while agitating and maintaining the temperature of the resultant mixture at a maximum of about 90.degree. C. to form 5-t-butyl-2-methylamino-1,3,4-thiadiazole;
- (iv) neutralizing said mixture with a neutralizing agent comprising an organic solvent and an alkaline substance dissolved in water to form an essentially neutralized two-phase, water-organic solvent system;
- and
- (v) separating from the neutralized system of (iv) an organic phase and recovering the compound 5-t-butyl-2-methylamino-1,3,4-thiadiazole therefrom.
A process for preparing the compound 5-t-butyl-2-methylamino-1,3,4-thiadiazole in high yield comprising:
- (i) adding 4-methyl-3-thiosemicarbazide to a solution of pivalic acid to form a slurry in a first vessel;
- (ii) placing a solution comprising polyphosphoric acid and concentrated sulfuric acid in a second vessel;
- (iii) feeding the contents of said first and second vessels concomitantly into a third vessel containing a heel, i.e., a reacted mixture having been formed previously by reacting 4-methyl-3-thiosemicarbazide with a solution of pivalic acid in the presence of a solution containing concentrated polyphosphoric acid and concentrated sulfuric acid to form 5-t-butyl-2-methylamino-1,3,4-thiadiazole in situ;
- (iv) agitating and maintaining the temperature of the overall mixture of (iii) at a maximum of about 90.degree. C., said overall mixture becoming enriched with respect to 5-t-butyl-2-methylamino-1,3,4-thiadiazole;
- (v) admixing the overall enriched mixture of (iv) with a neutralizing mixture comprising an organic solvent and an alkaline substance dissolved in water to form an essentially neutralized two-phase, water-organic solvent system;
- and
- (vi) separating from the neutralized system of (v) an organic phase and recovering the compound 5-t-butyl-2-methylamino-1,3,4-thiadiazole therefrom.
Dependencies are inferred from the claim text.