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ChemicalBook CAS DataBase List Sulfadoxine
2447-57-6

Sulfadoxine synthesis

2synthesis methods
Sulfadoxine, 4,5-dimethoxy-6-sulfanilamidopyrimidine (33.1.33), is synthesized by the standard scheme from 4-acetylaminobenzenesulfonyl chloride and 4-amino-5,6-dimethoxypyrimidine. However, the synthesis of 4-amino-5,6- dimethoxypyrimidine (33.1.31) is itself curious—it is synthesized from methyl ester of methoxyacetic acid. Interacting this with dimethyloxalate in the presence of sodium methoxide gives the methoxy derivative (33.1.25), and the pyrolysis of this compound gives the dimethyl ester of methoxymalonic acid (33.1.26). Reacting this with ammonia gives the diamide of methoxymalonic acid (33.1.27). Heterocyclization of the resulting product by a reaction with formamide in the presence of sodium ethoxide gives 4,6- dioxy-5-methoxypyrimidine (33.1.28), which is then transformed to 4,6-dichloro-5- methoxypyrimidine (33.1.29). The resulting 4,6-dichloro-5-methoxypyrimidine (33.1.29) undergoes a reaction with ammonia to make 4-amino-6-chloro-5-methoxypyrimidine (33.1.30), and the resulting compound is then reacted with sodium methoxide to make the desired 5,6-dimethoxy-5-aminopyrimidine (33.1.31). Reacting this with 4-acetylaminobenzenesulfonyl chloride and subsequent hydrolysis of the acetyl group in (33.1.32) gives sulfadoxine.

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Yield:2447-57-6 94.4%

Reaction Conditions:

with sodium carbonate in N,N-dimethyl-formamide at 85 - 90; for 4 h;Reagent/catalyst;Temperature;Solvent;

Steps:

2-6 Example 6 Preparation of Sulfadoxine Formula I

Respectively mix DMF 175.0g, sulfa sodium formula III 106.8g (0.55mol), 87.3g (0.50mol) of 4-chloro-5,6-dimethoxypyrimidine formula II and 53.0g of sodium carbonate were added to the reaction flask. After theaddition, the temperature was raised to 85-90 °C and reactedfor 4 hours. After the reaction, the vacuum is turned on, and DMF is recovered by distillation under reduced pressure. After the evaporation iscompleted, water is added. After stirring to dissolve, adjust the pH=7-8 with dilute acetic acid, cool, filter, and the filter cake can recover the sulfonamide. Transfer the filtrate to another reaction flask, adjust the pH=5.1-5.4 with dilute acetic acid, filtered, washed, and dried to obtain 146.5 g of sulfadoxine formula I, with a yield of 94.4%; HPLC purity 99.8%, without condensate formula VI impurities.

References:

CN112457259,2021,A Location in patent:Paragraph 0033-0047

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