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ChemicalBook CAS DataBase List Pipemidic acid
51940-44-4

Pipemidic acid synthesis

4synthesis methods
The synthesis of pipemidic acid involves a series of steps. First, ethyl 2,4-dichloropyrimidine-5-carboxylate is condensed and cyclized with ethyl β-ethylaminopropionate to yield 2-chloro-5-hydroxy-7,8-dihydro-8-ethylpyridine[2,3-d]pyrimidine-6-carboxylate. This compound is then brominated and subsequently condensed with piperazine. The resulting product is hydrolyzed and neutralized to obtain pipemidic acid.
-

Yield:-

Reaction Conditions:

with sodium hydroxide

Steps:

43 5,8-Dihydro-8-ethyl-2-(1-Piperazinyl)-5-oxopyrido [2,3-d]pyrimidine-6-carboxylic acid (compound 1).

EXAMPLE 43 5,8-Dihydro-8-ethyl-2-(1-Piperazinyl)-5-oxopyrido [2,3-d]pyrimidine-6-carboxylic acid (compound 1). Ethyl 5,8-dihydro-8-ethyl-5-oxo-2-(1-piperazinyl) pyrido[2,3-d]pyrimidine-6-carboxylate (5.0 g) was dissolved in 30 ml of a 7% aqueous solution of sodium hydroxide by heating at 90°C for 20 minutes. After cooling, the resulting solution was neutralized with acetic acid to yield a precipitate which was collected, and recrystallized from dimethylformamide. There is obtained 4.3 g of the product m.p 253° - 255°C.

References:

US3962443,1976,A

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