A kind of synthetic method of Florfenicol intermediate
A technology for florfenicol and intermediates, which is applied in the field of synthesizing florfenicol intermediates, can solve the problems of low yield of finished products, high production cost and environmental protection cost, unrecoverable tetrafluoropropionamide and the like
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[0087] The invention provides a kind of preparation method of Florfenicol intermediate (I), comprising the following steps:
[0088]
[0089] (1) in an organic solvent, compound (II) is reacted with an acylating reagent to form compound (III);
[0090] (2) in an organic solvent, in the presence of a catalyst, compound (III) is reacted with an oxidizing agent to form compound (IV);
[0091] (3) reacting compound (IV) with a fluorinating reagent in an organic solvent to form compound (V);
[0092] (4) In an organic solvent, compound (V) is prepared by acid hydrolysis and deprotection to obtain compound (I);
[0093] In the formula,
[0094] R 1 Benzyloxycarbonyl (Cbz), tert-butoxycarbonyl (Boc), Wat methoxycarbonyl (Fmoc), allyloxycarbonyl (Alloc), trimethylsilylethoxycarbonyl (Teoc), methyl (or ethyl) oxycarbonyl Or other alkoxycarbonyl amino protecting groups, phthaloyl (Pht), p-toluenesulfonyl (Tos), trifluoroacetyl (Tfa), o (p) nitrobenzenesulfonyl chloride (Ns), pent...
Embodiment 1
[0150] Synthesis of (4R,5R)-5-(tert-butyloxycarboxamido)-4-(4-thiamphenicolphenyl)-1,3,2-dioxathiolane-2,2-di Oxide (IV-1): In a 250mL three-necked flask, 5g (1R,2R)-2-(tert-butyloxycarboxamido)-1-(4-thiamphenylphenyl)-1,3-propanediol (II-1) was dissolved in 50 mL of dry dichloromethane, 40 mL of pyridine was added, the mixed system was cooled to -5°C, and 13.8 g of thionyl chloride was slowly added dropwise. After dropping, react at -5°C for 1h. After the reaction was completed, the filtrate was quenched by adding dilute hydrochloric acid (50mL), the aqueous phase was extracted by adding dichloromethane (60mL×3), the organic phases were combined, washed with saturated aqueous sodium bicarbonate (100mL), dried over anhydrous sodium sulfate, filtered, and reduced pressure Removal of solvent yielded crude sulfite. The obtained crude sulfite was dissolved in 10mL of water, 10mL of acetonitrile and 15mL of dichloromethane in a three-mixed system, and 4g of sodium periodate, 3mg ...
Embodiment 2
[0155] Synthesis of (4R,5R)-5-(dichloroacetamido)-4-(4-thiamphenylphenyl)-1,3,2-dioxathiolane-2,2-dioxide (IV-2): In a 250mL three-necked flask, 5g (1R,2R)-2-(dichloroacetamido)-1-(4-thiamphenylphenyl)-1,3-propanediol (II-2 ) was dissolved in 50 mL of dry dichloromethane, 40 mL of pyridine was added, the mixed system was cooled to -5°C, and 13.4 g of thionyl chloride was slowly added dropwise. After dropping, react at -5°C for 1h. After the reaction was completed, the filtrate was quenched by adding dilute hydrochloric acid (50mL), the aqueous phase was extracted by adding dichloromethane (60mL×3), the organic phases were combined, washed with saturated aqueous sodium bicarbonate (100mL), dried over anhydrous sodium sulfate, filtered, and reduced pressure Removal of solvent yielded crude sulfite. The obtained crude sulfite was dissolved in 10mL of water, 10mL of acetonitrile and 15mL of dichloromethane in a three-mixed system, and 4g of sodium periodate, 3mg of RuCl 3 .3H ...
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