Preparation method of (1R,3S)-3-aminocyclopentanol chiral acid salt
A technology of aminocyclopentanol and chiral acid, which is applied in the direction of carboxylate preparation, carboxylate preparation, sulfonate preparation, etc., can solve the problem of no separation of isomers, no chiral control of the synthesis method, and optical purity and low total yield, to achieve the effects of low production cost, easy large-scale production, easy separation and purification
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Embodiment 1
[0037] When R 1 Be ethyl, when R is phenyl, the preparation of formula V compound:
[0038]
[0039] Dissolve 100g of formula VI compound (R-mandelic acid) in 350ml of ethanol, add 28.4g of concentrated sulfuric acid at room temperature, then reflux for 5 hours to complete the reaction, cool to room temperature, and the resulting esterification solution (containing formula V compound) is directly used in Next reaction.
Embodiment 2
[0041] The preparation of formula IV compound:
[0042]
[0043] Add 91.4g of hydroxylamine hydrochloride to 550ml of methanol to obtain solution 1, and use it for later use; add 120g of potassium hydroxide to 300ml of ethanol to obtain solution 2 for later use; below 10°C, mix solution 1 and solution 2, and add dropwise The esterification solution (containing the compound of formula V) prepared in Example 1, after the dropwise addition, was reacted at 15-25° C. for 2 hours, and the reaction was terminated. The pH of the reaction solution was adjusted to 7.0-7.5, concentrated, and the concentrate was treated with acetic acid Ethyl ester was recrystallized at room temperature to obtain the compound of formula IV (89 g, molar yield 81%).
Embodiment 3
[0045] The preparation of formula III compound:
[0046]
[0047]The sodium periodate of 129g is dissolved in the mixed solvent of the water of 300ml and the methanol of 600ml, the cyclopentadiene of 79.4g is added, stir well, the methanol solution of compound of formula IV is added dropwise (100g compound of formula IV is dissolved in 400ml of Methanol), after the dropwise addition, react at 15-25°C for 15-18 hours, finish the reaction, filter, concentrate, add a mixed solvent of 50ml of methanol and 500ml of water to the concentrated mother liquor, stir, filter, and Add 100ml of dichloromethane to the cake, reflux and stir for 1 hour, then dropwise add 600ml of tertiary methyl ether solution, crystallize, collect the precipitated crystals, and dry to obtain the compound of formula III (118.7g, molar yield 86.1%, isomeric body is less than 0.50%).
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