Methyl allophanate

Methyl Allophanate. Three hundred five milliliters of methyl chlorocarbonate (4.0 mols) and 480 g. of finely powdered urea (8.0 mols) are placed in a 2-1. standard-taper round-bottomed flask equipped with a 60-cm. reflux condenser. The mixture is heated on a steam bath for 90 minutes. Four hundred milliliters of water is added to the warm reaction cake to decompose any unreacted chlorocarbonic ester and to remove by solution both unchanged urea and urea hydrochloride, t Methyl allophanate remains behind as a relatively water-insoluble residue. The suspension is filtered and the white product washed with three 250-ml. portions of water, then with 95% ethanol (two 250-ml. portions), and finally with 500 ml. of ethyl ether. It is air-dried. The yield of product will vary from 227 to 274 g. (48 to 58%). The product thus obtained is pure enough to use as the starting material for other reactions. It can be further purified by recrystallization from hot water using 27.5 ml. of water per gram of compound (85% recovery m.p. 215 to 216° with decomposition). 

Allophanate Methyl allophanate Biuret Dimethyl biuret Tetramethyl biuret L-Ascorbic acid 2-(2H-Benzotriazole-2-yl)-4,6-ditertpentylphenol Decanedioic acid, bis(2,2,6,6-tetramethyl-l-(octyl-oxy)-4-piperidinyl)ester Bis (l,2,2,6,6-pentamethyl-4-pi-peridinyl)-[[3,5-bis(l,l-dimethyl-ethyl)-4-hydroxyphenyl]methyl]butylmalonate Tinuvin 328 Tinuvin 123 Tinuvin 144... 

Codonopsis pilosula (Franch.) Nannfeldt C. tangshen Oliv. China Taraxeryl acetate, friedelin, n-butyl allophanate, inulin, sucrose, amino acids, stigmasterol, spinasterol, methyl palmitate, taraxerol.48 For amnesia, anorexia, asthma, cachexia, cancer, impotence, insomnia, palpitations. 

The free base allophanylhydrazide was prepd by Audrieth et al (Refs 3 5) in good yield (80%) by hydrazinolysis of methyl- or ethyl- allophanate under reflux. Some esters and salts of allophanylhydrazide were also prepd (Ref 3, pp 17-27 42-6)... 

Allophanyl hydrazide has been prepared previously as the hydrochloride by the zinc-hydrochloric acid reduction of 1-nitrobiuret.1 The new procedure2,3 outlined here entails the hydrazinolysis of allophanic esters in alcoholic solution. Excellent yields (80 to 84%) of allophanyl hydrazide are obtainable with a minimum of difficulty using readily available starting materials. The methyl and ethyl allophanates are prepared from urea and the corresponding chlorocarbonic esters.4... 

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