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ChemicalBook CAS DataBase List 1-Methyl-1H-pyrazole-4-carbaldehyde
25016-11-9

1-Methyl-1H-pyrazole-4-carbaldehyde synthesis

6synthesis methods
Using cyclopropyl methyl ketone and dimethoxy-N, N-dimethylmethylamine as starting materials, the target product 1-Methyl-1H-pyrazole-4-carbaldehyde was obtained through aldol condensation, hydrazine condensation cyclization, selective methylation reaction and Vilsmeier-Hack reaction in sequence, with a total yield of up to 48.0%.
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Yield:25016-11-9 87%

Reaction Conditions:

with caesium carbonate in N,N-dimethyl-formamide at 60;

Steps:

A PREPARATION OF INTERMEDIATE 48

To a solution of lH-pyrazole-4-carbaldehyde (1.00 g, 10.4 mmol) in DMF (40 mL) was added iodomethane (1.48 g, 10.4 mmol) and CS2CO3 (10 g, 31.2 mmol). After stirring at 60°C overnight, the reaction mixture was added water (20 mL) and extracted with EtOAc (50 mL x 3). The organic phase was washed with brine, dried over Na2S04 and concentrated to give intermediate 48 (1.00 g, 87% yield).

References:

WO2018/50684,2018,A1 Location in patent:Page/Page column 67

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