2-羟基-5,7-二甲基-1,2,4-三唑[1,5-a]嘧啶的合成

Synthesis of 2-hydroxy-5,7-dimethyl-1,2,4-triazolopyrimidine

2-羟基-5,7-二甲基-1,2,4-三唑[1,5-a]嘧啶(TPO)是三唑并嘧啶类衍生物的重要中间体,以氨基脲盐酸盐为起始原料,经环化、硝化、还原及并环得到.氨基脲盐酸盐先与甲酸成环,制得中间1,2,4-三唑-5-酮(TO),产率86.5%;用发烟硝酸硝化得3-硝-基1,2,4-三唑-5-酮(NTO),产率90.1%;雷尼镍催化下加氢还原得3-氨基-5-羟基-1,2,4-三唑(ATO),产率88.0%;最后与乙酰丙酮环合制得标题化合物TPO,产率86.0%.该方法原料易得、操作简便,总收率较高,达到59.0%.

The 2-hydroxyl-5,7-dimethyl-1,2,4-triazolo[- 1,5-a] pyrimidine （TPO） is an important intermediate for triazolopyrimidine derivatives. It was synthesized from amidourea hydrochloride by way of ring closure, nitration, deoxidization and cyclization. First, amidourea hydrochloride reacted with formyl acid to form 1,2,4-triazol-5-one （TO） with a yield of 86. 5%. Second, the TO was nitrated using fuming nitric acid to prepare the 3-nitro-1,2,4-triazol-5-one （NTO） with a yield of 90. 1%. Third, NTO was reduced by using Hz in the presence of Raney Ni to obtain the 3-amino-5-hydroxyl-1,2,4-triazole （ATO） with a yield of 88.0%. The TPO was then synthesized from ATO together with acetyl acetone with a yield of 86.0%. The overall yield was 59.0%. The synthesis route used is simple. The reaction conditions are mild. And the raw materials are cheap and easy to obtain.