The ‐NHSO3H groups in heparin are replaced by ‐NH2 groups. Prepn of sodium salt by methanolysis of sodium heparinate and saponification: Velluz et al., Compt. Rend. 247, 1521 (1958); from sodium heparinate heated with HCl, neutralized with NaHCO3 and dialyzed against running water: Foster et al., J. Chem. Soc. 1961, 1204; from sodium heparinate demineralized with Dowex 50 resin: GB 863235 (1961 to UCLAF).