Ornithine prodn. from alkoxycarbonyl-(2)-alkoxy-pyrrolidine derivs. - by reacting with hydrogen cyanide and ammonia and hydrolysing the product

摘要

In the prodn. of ornithine in the form of its salts, a 1-alkoxycarbonyl-2-alkoxypyrrolidine of formula (I): (where R1 is 1-4C alkoxy and R2 is 1-4C alkyl) is reacted with at least equimolar amts. of HCN and NH3 and opt. CO2 in aq. or aq. alcoholic reaction medium at ca 70-150 degrees C (pref. ca 90-120 degrees C) under substantially autogenic pressure, and the reaction prod. (an aminonitrile when NH3/HCN is used, or a hydantoin when NH3/HCN/CO2 is used) is hydrolysed in a conventional manner. In an example, 79.5g (I, R1=OCH3, R2=CH3), 79g NH3-HCO3 and 16g HCN in 300 ml water are autoclaved 8 hrs. at 100 degrees to give 69g 5-(3-methoxycarbonylpropyl)hydantoin. Hydrolysis of this with conc. HCl at 160 degrees gives ornithine hydrochloride in 89.6% yield.