Reaction of 6-aminouracils (I) with alkyl or aryl isothiocyanates afforded 6-amino-5-substituted thiocarbamoyluracils (II), which were oxidized with bromine or hydrogen peroxide to afford 3-(substituted) aminoisothiazolo [3, 4-d] pyrimidin-4, 6-(5H, 7H)-diones (III). Alkylation of III afforded 3-(N, N-disubstituted) amino derivatives (V). Further oxidation of 1, 3-diethyl-3-dimethylamino-or-3-methylaminoisothiazolo [3, 4-d] pyrimidin-4, 6-(5H, 7H)-dione (Vb or IIIb) with hydrogen peroxide afforded 1, 3-diethyl-5-alkylcarbamoyl-5-hydroxybarbituric acid (Xa or Xb). Treatment of Xa with Raney nickel afforded 1, 3-diethyl-5-dimethylcarbamoylbarbituric acid (XII).
6-
氨基尿
嘧啶(I)与烷基或芳基异
硫氰酸酯反应生成6-
氨基-5-取代
硫代
氨基甲酰尿
嘧啶(II),后者与
溴或
过氧化氢氧化生成3-(取代)
氨基
异噻唑并[3,4-d]
嘧啶-4,6-(5H,7H)-二酮(III)。III的烷基化反应生成3-(N,N-二取代)
氨基衍
生物(V)。1,3-
二乙基-3-二甲基
氨基或3-甲基
氨基
异噻唑并[3,4-d]
嘧啶-4,6-(5H,7H)-二酮(Vb或IIIb)与
过氧化氢进一步氧化生成1,3-
二乙基-5-烷基
氨基甲酰-5-羟基
巴比妥酸(Xa或Xb)。Xa与雷尼
镍反应生成1,3-
二乙基-5-二甲基
氨基甲酰
巴比妥酸(XII)。