The attempts of the cyano group reduction in 1-cyanoethyl 5-substituted uracil derivatives

A variety of reductants for the reduction of 1-cyanoethyl-5-substituted uracil derivatives has been examined. Commonly used reductants, borane dimethyl sulphide complex, ammonium formate and sodium borohydride were applied. For the most investigated 5-substituted uracil derivatives the reduction with sodium borohydride has shown the highest efficiency when nickel(II) chloride as a catalyst has been applied. The reactions were performed in methanol at decreased temperature in the presence of di-tert-butyl carbonate as a "trapping" agent. The Boc-protected 1-(3-aminopropyl)pyrimidine-2, 4(1H,3H)-diones were synthesized in moderate to high yields.