Sulfuric Acid → 2,4-Diaminopyrimidin-5-ol

Participants

Reaction Steps

A stirred solution of 23.0 grams (0.235 mole) of concentrated sulfuric acid and about 18 mL of water was heated to reflux, and 48.5 grams (0.235 mole) of 2,4-diamino-5-pyrimidinyl hydrogen sulfate was added in one portion. Upon completion of addition, the reaction mixture was heated at reflux for ten minutes and then was immediately cooled in an ice-water bath. The resultant solid was collected by filtration, and the filter cake was washed with 100 mL of cold water. The solid was dried, yielding 34.0 grams of 2,4-diamino-5-hydroxypyrimidine hydrosulfate salt, mp 290° C., dec. The NMR spectrum was consistent with the proposed structure.

Provenance & Evidence