Реакция #1375

Уравнение реакции

ethyl 1-cyclopropyl-6,7-difluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate

hydrochloric acid

→

1-cyclopropyl-6,7-difluoro-5-methyl-1,4,-dihydro-4-oxoquinoline-3-carboxylic acid

Выход 92.7%

Растворители

acetic acid

Условия реакции

Обработка

1. 1
   Температураthe mixture is refluxed for 2 hours
2. 2
   ТемператураAfter cooling
3. 3
   Другоеthe precipitated crystals are isolated
4. 4
   Промывкаwashed with water, ethanol, and diethyl ether in this order

Методика

To ethyl 1-cyclopropyl-6,7-difluoro-5-methyl-1,4-dihydro-4-oxoquinoline-3-carboxylate (1.9 g) are added 90% acetic acid (20 ml) and conc. hydrochloric acid (5 ml) and the mixture is refluxed for 2 hours. After cooling, the precipitated crystals are isolated, washed with water, ethanol, and diethyl ether in this order to give 1-cyclopropyl-6,7-difluoro-5-methyl-1,4,-dihydro-4-oxoquinoline-3-carboxylic acid (1.6 g), as colorless needles, m.p. 294°-298° C.

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