Hydroxylamine hydrochloride Hydroxyurea

The improved method herein described is adapted from the procedure of Runti and Deghenghi. Hydroxyurea has been prepared from potassium cyanate and hydroxylamine hydrochloride. A lower melting isomeric substance, m.p. 71°, has been described." " The structure NH2CO2NH2 has been proposed for this low-melting substance. 

The procedure may be illustrated by the following equations relating to the preparation of hydroxyurea from hydroxylamine hydrochloride ... 

Equation (1) shows the simple conversion of a quaternary ammonium anion exchange resin from the chloride form to the cyanate form. Equation (2) shows the reaction of the resin in the cyanate form with hydroxylamine hydrochloride whereby hydroxyurea is formed and the anion Cl is retained by the quaternary resin. 

Hydroxyisophthauc acid, 40, 48 Hydroxylamine hydrochloride, reaction with ethyl carbamate to form hydroxyurea, 40, 60... 

Hydroxyurea Hydroxyurea (30.6.1) is made by reacting sodium cyanate with hydroxyl-amine. In this reaction, hydroxylamine hydrochloride and a basic ion-exchange resin are used [140,141],... 

Hydroxyurea (m.p. 137-141°) is obtained by preparing a solution of hydroxylamine hydrochloride, urethane, and sodium hydroxide in water, letting it stand at room temperature for 3 days, carefully neutralizing with hydrochloric acid, extracting... 

PClg added all at once under Ng in the dark to a suspension of vitamin A acid in abs. benzene, stirred 3 hrs. at 20-25°, the resulting soln. of the acid chloride treated with Ag-cyanate, stirred vigorously 5 hrs. in a closed flask in the dark, filtered, the soln. of the acylisocyanate obtained added dropwise during 15 min. to a soln. of hydroxylamine hydrochloride in abs. pyridine, and stirred overnight at room temp, in a closed flask in the dark N-retinoyl-N -hydroxyurea. Y 89.4%. R. Miller, Chem. Therap. 9, 298 (1974). 

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