Hydrochloric Acid → 4-(1-Methyl-2,6-dioxo-1,2,6,7-tetrahydro-3H-purin-3-yl)butanoic acid

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Reaction Steps

An oily suspension of 1-methyl-3-(carboethoxypropyl)-7-(pivaloyloxymethyl)xanthine (508 mg) in 2N NaOH(36.2 ml) was heated under nitrogen at 95°-100° for 2 hrs. The oil dissolved and the reaction was shown to be complete by TLC. After cooling the reaction mixture, it was acidified to pH 2-3 with 15 ml 12% hydrochloric acid and the solution extracted with 3×5 ml chloroform to remove the pivalic acid. After washing the chloroform extracts with 5 ml 0.5 N HCl, the aqueous solutions were combined and stripped to dryness and the residue dried in vacuo at room temperature. The crude product was dissolved in about 22 ml hot water, decolorized and concentrated to 15 ml, at which time 159 mg of a crystalline product was obtained upon cooling. m.p. 220°-221°.

Provenance & Evidence