Yield:58909-39-0 92.7%

Reaction Conditions:

with dmap;N,N,N,N,-tetramethylethylenediamine;sodium methylate in methanol;ethanol at 15 - 55; for 4 h;Temperature;Solvent;Reagent/catalyst;

Steps:

1-3; 1-5 Example 1
Add 10.5g of 2-methylthiosemicarbazide, 15.3g of diethyl oxalate, 31.5g of methanol, and 31.5g of ethanol to the reaction flask, reduce to 15°C, and add mixed alkali catalyst (including 36.8g of sodium methoxide, 0.05g of DMAP, TMEDA 0.05g) 1.5h, after dripping, heat up to 55 for cyclization reaction for 2.5h, acidify with hydrochloric acid to pH=1.0, cool down to 5 and filter with suction to obtain crude thiotriazinone ring, which is dissolved in 63g distilled water at 70 and cooled Crystallize at 15°C and filter with suction to obtain a wet product of thiotriazinone ring, and dry at 100°C for 3 hours to obtain 14.75 g of dry product of thiotriazinone ring, with a purity of 99.6% and a yield of 92.7%.

References:

CN112759558, 2021, A Location in patent:Paragraph 0017; 0035-0050

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