Ethylene Glycol → 5-(5-Hydroxymethyl-2-n-propoxyphenyl)-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]-pyrimidin-7-one

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Reaction Conditions

Reaction Steps

To a solution of 5-(5-chloromethyl-2-n-propoxyphenyl)-1-methyl-3-n-propyl-1,6-dihydro-7H-pyrazolo[4,3-d]pyrimidin-7-one (0.5 g, 0.0013 mol) in dimethyl sulphoxide (10 ml) was added sodium hydroxide (0.26 g, 0.0065 mol) and ethylene glycol (0.41 g, 0.0065 mol). The reaction mixture was heated at 100° C. for 6 hours, allowed to cool and poured into water (50 ml), then the aqueous mixture extracted with ethyl acetate (3×30 ml). The combined extracts were filtered, dried (Na2SO4) and evaporated under vacuum to provide an oil which was purified by chromatography on silica gel (6 g), using a methanol in dichloromethane elution gradient (0-3% methanol). The solid product was crystallised from hexane-ethyl acetate to afford the title compound as a white solid (2%), m.p. 174°-175° C. Found: C,63.97; H,6.66; N,15.57. C19H24N4O3 requires C,64.03; H,6.79; N,15.72%.

Provenance & Evidence