Methanol → 1-(Hydroxymethyl)-2-phenylpyrazolo[1,5-c]quinazolin-5(6H)-one

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Reaction Steps

To a suspension of 4.0 g (0.0139 mole) of 5,6-dihydro-5-oxo-1-phenylpyrazolo[1,5-c]quinazolin-2-carboxaldehyde (prepared as in Example 1A) in 300 ml of methanol (at 0°) there is added 2.5 g (0.066mole) of sodium borohydride. The suspension is stirred at 0° for 15 minutes and then overnight at room temperature. Another 2.5 g of sodium borohydride is added, and, after 6 hours another 2.5 g, and stirring continued overnight. The reaction mixture is treated with 200 ml of water, the methanol stripped, the solid (3.7 g) filtered and dried. This material is suspended in 500 ml of absolute ethanol, the mixture cooled to 0°, treated with 2.5 g of sodium borohydride, and stirred for 5 hours at room temperature, after which reduction is complete. The suspension is treated with 250 ml of water and stripped to a low volume. The precipitate is filtered, washed with water and dried (wt. 2.5 g). Recrystallization from absolute ethanol containing 2% benzene gives 2.1 g of analytically pure material, which contains 1 mole of water, m.p. 267°-270° (d).

Provenance & Evidence