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ChemicalBook CAS DataBase List 1,3-Dimethyl-1H-pyrazol-5-amine
3524-32-1

1,3-Dimethyl-1H-pyrazol-5-amine synthesis

8synthesis methods

5-Amino-1,3-dimethylpyrazole can be used as an intermediate in organic synthesis, mainly in laboratory research and chemical production process. It was prepared from the condensation of methylhydrazine with Mannich base by  stirring in 3-aminocrotononitrile for 40min at 90-95℃.

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Yield:3524-32-1 240 g. (71%)

Reaction Conditions:

in ethanol;benzene

Steps:

1.1 5-Amino-1,3-dimethylpyrazole (Compound CXII)
Step 1 5-Amino-1,3-dimethylpyrazole (Compound CXII) A mixture of 250 g. (3.04 moles) of 3-aminocrotonitrile, 152.5 g. (3.3 moles) of methylhydrazine and 1 l. of absolute ethanol is refluxed for 8 hours (until the evolution of ammonia ceases) and cooled to 20°-25° C. The ethanol is evaporated at reduced pressure, and the residual oil is triturated with ~300 ml. of benzene. The resulting yellow-orange solid product is collected by filtration and vacuum dried at 45° C. to obtain the product (240 g. (71%)), m.p. 74°-76° C.

References:

Sandoz Pharm. Corp. US4822799, 1989, A

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