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US 9,000,160 B2Granted
Process for the preparation of 2-amino-5,8-dimethoxy[1,2,4]triazolo[1,5-c]pyrimidine from 4-chloro-2,5-dimethoxypyrimidine
AssigneeDow AgroSciences LLC
InventorsDouglas C. Bland, Gary Roth, Craig Bott, Christopher T. Hamilton, Joseph Neuman
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Abstract
2-Amino-5,8-dialkoxy[1,2,4]-triazolo[1,5-c]pyrimidines are manufactured from 4-chloro-2,5-dialkoxypyrimidines in a process that avoids hydrazine and cyanogen halide.
Claims21
A process for the preparation of 2-amino-5,8-dialkoxy[1,2,4]-triazolo[1,5-c]-pyrimidines of the formula (I),
- wherein R is C1-C4 alkyl
- comprising:
- i) contacting a 4-chloro-2,5-dialkoxypyrimidine of the formula
- wherein R is as previously defined
- with a salt of cyanamide in a polar aprotic solvent to provide a 2,5-dialkoxy-4-cyanoaminopyrimidine of the formula
- in which R is as previously defined;
- ii) contacting the 2,5-dialkoxy-4-cyanoaminopyrimidine with either hydroxylamine as a free base or hydroxylamine salt in the presence of a base to provide a 2,5-dialkoxy-4-hydroxyguanidinylpyrimidine of the formula
- wherein R is as previously defined;
- and
- iii) cyclizing the 2,5-dialkoxy-4-hydroxyguanidinylpyrimidine by treating with an alkyl chloroformate to provide the 2-amino-5,8-dialkoxy[1,2,4]-triazolo[1,5-c]pyrimidine.
7 more elements
A process for the preparation of 2-amino-5,8-dialkoxy[1,2,4]-triazolo[1,5-c]-pyrimidines of the formula (I),
- wherein R is C1-C4 alkyl
- comprising:
- cyclizing a 2,5-dialkoxy-4-hydroxyguanidinylpyrimidine
- of the formula
- wherein R is as previously defined;
- by treating with an alkyl chloroformate to provide the 2-amino-5,8-dialkoxy[1,2,4]-triazolo[1,5-c]pyrimidine.
3 more elements
A compound of the formula
- in which R represents C1-C4 alkyl.
A compound of the formula
- in which R represents C1-C4 alkyl.
Dependencies are inferred from the claim text.