The Synthetic Study Of3-Amino-triazole-5-carboxylic Acid

3-amino-triazole-5-carboxylic acid， an important pharmaceuticalintermediate，is widely used for synthesis of pharmaceuticals, dyes, pesticidesand so on. In recent years, demands for3-amino-trizaole-5-carboxylic acidhave been increasingly growing both the traditional and foreign markets.However, complex process, low yield and instable quality are caused by thetraditional methods of producing3-amino-triazole-5-carboxylic acid throughhydrazine and aminoguanidine processes greatly restricted the production anddevelopment of3-amino-triazole-5-carboxylic acid. Therefore, it’s significantto study and improve the synthesis process of3-amino-triazole-5-carboxylicacid.In this paper,3-amino-triazole-5-carboxylic acid was prepared from limenitrogen, hydrazine hydrate and oxalic acid by acylation and cylization withthe condition of aminoguanidine and oxalic acid. The synthesis processparameters were optimized and the structure of relevant compounds wascharacterized by IR and MS. The results were showed as follows:（1）The synthesis of optimum conditions of aminoguanidine: Waterconsumption is100ml, the reaction temperature is45°C, n (hydrazinehydrate): n (lime nitrogen) is1.2, the pH value is7.2~7.5, heat for threehours at70°C. The optimum conditions of precipitation crystallizationreaction: temperature is10°C, the crystallization time for4hour. In thiscondition, the yield of aminoguanidine bicarbonate is96%and the purity is98%.（2）3-amino-triazole-5-carboxylic acid was proposed by acylating andcyclizating in condition of aminoguanidine and oxalic acid. Acylation ofoptimal conditions: n (aminoguanidine): n (oxalicacid) is1:1.3, the motherliquor was applied twice, temperature is100°C, and reaction time is6hours. cyclization reaction better conditions are as follows: m (acylation): m (waterconsumption)=1:5, pH value after the alkaline is10.5, then pH is2.0afteradding acid, sulfuric acid dropping temperature is60°C, dropping time is60min. In this condition, the yield of3-amino-triazole-5-carboxylic acid was77%.（3）The structure of product was confirmed by IR and MS, and thecontent of the product was analyzed, the purity of aminoguanidinebicarbonate is98%, the purity of the ring compounds is95%.