- A solid phosgene and thiosemicarbazide reaction for the preparation of 2 - hydroxy - 5 - amino - 1, 3, 4 - thiadiazole method
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The invention relates to the preparation of 2-hydroxy-5-amino-1,3,4-thiadiazole. The preparation method comprises the following steps: taking thiosemicarbazide as the substrate, then adding thiosemicarbazide into a dichloromethane solution containing solid phosgene and triethanolamine, then adding a saturated potassium hydroxide solution, mixing, stirring to carry out reactions, and extracting the reaction products by ethyl acetate to obtain the target product. The provided novel method prepares 2-hydroxy-5-amino-1,3,4-thiadiazole from solid phosgene and thiosemicarbazide, has the advantages of mild conditions, convenience, low cost, high yield, and convenient and efficient post treatment, and is suitable for industrial production. The prepared 2-hydroxy-5-amino-1,3,4-thiadiazole can be used to prepare 1,3,4-thiadiazole drugs.
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Paragraph 0027-0031
(2018/02/23)
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- Synthesis of 2-(2',3'-Dihydroxypropyl)-5-amino-2H-1,2,4-thiadiazol-3-one and 3-(2',3'-Dihydroxypropyl)-5-amino-3H-1,3,4-thiadiazol-2-one
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The synthesis of two new acyclic nucleoside analogs, 2-(2',3'-dihydroxypropyl)-5-amino-2H-1,2,4-thiadiazol-3-one (1) and 3-(2',3'-dihydroxypropyl)-5-amino-3H-1,3,4-thiadiazol-2-one (2), is reported.The first compound, 1, was obtained by reaction of 3-chloro-1,2-propanediol with the sodium salt of 5-amino-2H-1,2,4-thiadiazol-3-one (3) in anhydrous dimethylformamide.Similarly, 5-amino-3H-1,3,4-thiadiazol-2-one (4) reacted with 3-chloro-1,2-propanediol to give 2.The thiadiazole 4 was prepared by condensation-cyclization of hydrazothiodicarbonamide (9).
- Parkanyi, Cyril,Yuan, Hui Liang,Cho, Nam Sook,Jaw, JIn-Hwa J.,Woodhouse, Tamar E.,Aung, Thomas L.
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p. 1331 - 1334
(2007/10/02)
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- Process for the preparation of 1,3,4-thiadiazolone derivatives
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A process for preparing 1,3,4-thiadiazolone compounds of the formula STR1 comprising reacting a 2-alkoxy-1,3,4-thiadiazole of the formula STR2 with hydrogen chloride in non-aqueous organic solvent under non-aqueous conditions at a temperature of from 0° t
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