796845-50-6Relevant articles and documents
Preparation method of 2-(4-bromo-1-methyl-1H-pyrazol-5-yl)ethanamine
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Paragraph 0019; 0025; 0033, (2017/08/30)
The invention relates to a preparation method of 2-(4-bromo-1-methyl-1H-pyrazol-5-yl)ethanamine. The method comprises the following steps: reacting 1-methylpyrazole used as a raw material to obtain 1-methyl-1H-pyrazole-5-carbaldehyde; adding piperidine and pyridine to obtain a solid 3-(1-methyl-1H-pyrazole-5-yl) acrylic acid; further, adding palladium on carbon into a methanol solution, and introducing hydrogen to obtain 3-(1-methyl-1H-pyrazol-5-yl) propionic acid; furthermore, reacting under roles of bromine and saturated sodium sulphite solution, and performing spinning drying to obtain a solid 3-(4-bromo-1-methyl-1H-pyrazol-5-yl) propionic acid; adding thionyl chloride, tetrahydrofuran, and stronger ammonia water, reacting, dissolving out methyl alcohol, purifying silica gel, eluting ethyl acetate in sequence to obtain 3-(4-bromo-1-methyl-1H-pyrazol-5-yl) propanamide; finally adding NaOH and bromine, and performing ice-bath to obtain 2-(4-bromo-1-methyl-1H-pyrazol-5-yl)ethanamine. The method has the advantages of being clear in steps, little in waste, high in yield, easy to operate and capable of saving raw materials.
CEPHEM COMPOUNDS
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, (2010/02/09)
The present invention relates to a compound of the formula [I]: wherein R1 is lower alkyl which may have suitable substituent(s), R2 is amino, protected amino or guanidino, R3 is carboxy or protected carboxy, R4 /sup
