Water → 4(1H)-Quinolinone, 3-hydroxy-1-methyl-

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Reaction Steps

Sodium methoxide (17.75 g) was added to a stirred solution of 2-[2-(N-methylformamido) phenyl]-2-oxoethyl benzoate, obtained as described in Example 2a-d, (186 g) in dichloromethane (1300 ml) at 0° under nitrogen resulting in an exotherm to 25 to 30°. The mixture was recooled at 0° and a second portion of sodium methoxide (17.75 g) added resulting in a further exotherm and the resultant mixture stirred for 1 hour. Sodium methoxide (35.5 g) was then again added in two equal portions and the resultant mixture stirred at 0 to 10° for 1 hour. Water (1860 ml) was added over 70 minutes maintaining the temperature below 6°. The phases were separated and the dichloromethane phase was extracted with aqueous sodium hydroxide (0.5M, 930 ml). The combined aqueous phase and extract were washed with dichloromethane (930 ml) and then cooled to 0°. Hydrochloric acid ( 5M, 300 ml) was added dropwise to pH 3 to 4 followed by aqueous sodium hydroxide (5M, 38 ml) and then aqueous sodium bicarbonate (1M, 250 ml) to pH 8. The resultant solid was collected by filtration and washed with water (3×200 ml) to give 3-hydroxy-1-methyl-4-quinolone, m.p. 239°-241°.

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