36315-01-2Relevant articles and documents
Sorption and degradation of azimsulfuron on iron(III)-rich soil colloids
Pinna, M. Vittoria,Pusino, Alba,Gessa, Carlo
, p. 8081 - 8085 (2004)
The sorption of N-[[(4,6-dimethoxypyrimidin-2-yl)amino]carbonyl]-1-methyl- 4-(2-methyl-2H-tetrazole-5-yl)1H-pyrazole-5-sulfonamide (AZS) on an iron oxide, iron(III)-humate, and an Fe3+-saturated clay was studied using a batch equilibrium method. Generally, 20 mg of each colloid was equilibrated with 20 mL of AZS solution (1.5-12.7 μM). The sorption on iron-montmorillonite and iron oxide was rapid, and the equilibrium was attained within 1.5 and 5 h, respectively. In the case of Fe-saturated humic acid the equilibrium time was 20 h. After equilibration, the phases were centrifuged (19000g, 15 min) and the supernatant was sampled and analyzed by HPLC. The values of Freundlich constants indicate that iron oxide (Kads = 199-5) shows the highest sorptive capacity toward AZS, followed by iron(III)-clay (Kads = 146.6) and iron(III)-humate (Kads = 108.2). With elapsing time, AZS degradation was observed in all colloidal suspensions. Iron-humate (t1/2 = 136 h) is most effective in promoting AZS degradation, followed by iron oxide (t 1/2 = 204 h) and iron-clay (t1/2 = 385 h). The metabolites 2-amino-4,6-dimethoxypyrimidineand 1-methyl-4-(2-methyl-2H-tetrazole-5-yl)-1H- pyrazole-5-sulfonamide, arising from a hydrolytic cleavage of the sulfonylurea bridge, were the only byproducts observed. A Fourier transform infrared study suggests that the sorption of AZS on iron-clay involves the protonation of one of the two basic pyrimidine nitrogens induced by the acidic water surrounding the saturating Fe3+ ions. Instead, the formation of a six-membered chelated complex favors the sorption of AZS on iron oxide.
Kinetic study on acid-base catalyzed hydrolysis of azimsulfuron, a sulfonylurea herbicide
Khan, M. Niyaz,Bakar, Baki B.,Yin, Fenny W. N.
, p. 253 - 260 (1999)
Pseudo-first-order rate constants (kobs) for hydrolysis of a sulfonylurea herbicide, azimsulfuron, AZIM, {N-[[(4,6-dimethoxy-2-pyrimidinyl)amino]carbony]-1-methyl-4- (2-methyl-2H-tetrazol-5-yl)-1H-pyrazole-5-sulfonamide} (AZS) follow an empirical relationship: kobs = α1+α2[-OH]+α3 [-OH]2 within the [NaOH] range of 0.1-2.0 M at different temperatures ranging from 40 to 55 °C. The contribution of α3[-OH]2 term is small compared with α2[-OH] term and this turns out to be zero at 60 °C. Pseudo-first-order rate constants (kobs) for hydrolysis of AZS within the [H+] range from 2.5×10-6 to 1.4 M follow the relationship: kobs = (α1Ka+β1[H*]+β2 [H+]2)/([H+]+Ka) where pKa = 4.37 at 50 °C. The value of β1 is nearly 25 times larger than that of α1. The rate of alkaline hydrolysis of AZIM is weakly sensitive to ionic strength.
Preparation method of 2-amino-4, 6-dimethoxypyrimidine
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Paragraph 0028; 0031; 0032; 0035; 0036; 0039, (2021/03/30)
The invention discloses a preparation method of 2-amino-4, 6-dimethoxypyrimidine, which comprises the following steps: S1, reacting malononitrile with methanol and hydrogen chloride to prepare 1, 3-dimethoxymalonamidine dihydrochloride; S2, controlling the pH value to be 5-6, and adding cyanogen chloride to react with 1, 3-dimethoxypropane diamidine dihydrochloride, so as to prepare 3-amino-3-methoxy-N-nitrile-based 2-propylamidine; and S3, carrying out cyclization on the 3-amino-3-methoxy-N-nitrile-2-propylamidine to obtain 2-amino-4, 6-dimethoxy pyrimidine; wherein the reaction in the step S1-S3 is carried out in an organic solvent. The cyanide chloride is adopted to replace cyanamide in a traditional method, the water content of a synthesis system is reduced, the amount of three wastesis reduced, a target product is synthesized through a one-pot method, damage caused by high corrosivity of 1, 3-dimethoxypropane diamidine dihydrochloride is avoided, the synthesis time is shortened,and the production efficiency is improved.
Preparation method for 2-amino-4,6-dimethoxypyrimidine
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Paragraph 0050-0053; 0056-0059, (2020/03/05)
The invention provides a preparation method for 2-amino-4,6-dimethoxypyrimidine. The method comprises the following steps: by using malonate diester (II) and a di-substituted methylene guanidine salt(III) as raw materials, performing a cyclization reaction under the action of a base, performing a methylation reaction with a methylation reagent to prepare 2-di-substituted methylene amino-4,6-dimethoxypyrimidine (IV), and performing hydrolysis in an acidic aqueous solution to prepare the 2-amino-4,6-dimethoxypyrimidine (I). The raw materials used in the method are cheap and easy to obtain, andthe costs are low; the preparation method is simple, the steps are few, the conditions are easy to realize, and the operational safety is good; and the product yield and purity are high, the amount ofwastewater is small, and the method is environmentally friendly and suitable for industrial production.
Method for preparing 2-amino-4,6-dimethoxy pyrimidine
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Paragraph 0024-0052, (2019/10/01)
The invention relates to a method for preparing 2-amino-4,6-dimethoxy pyrimidine. The method comprises the following steps: by taking 3-amino-3-methoxy-N-cyano-2-pyridinepropanimidamide as a raw material, and carrying out cyclization under the action of a catalyst, so as to generate the 2-amino-4,6-dimethoxy pyrimidine. By adopting the method, not only is a production cycle shortened, but also thereaction temperature is reduced, in addition, the product purity is improved, an economic and energy-saving route is provided for industrial production of the 2-amino-4,6-dimethoxy pyrimidine, and good economic benefits can be made. The structural formula of the 2-amino-4,6-dimethoxy pyrimidine is shown in the specification.