The invention provides a preparation method of a pidotimod crude drug. The preparation method mainly comprises a condensation reaction and a hydrolysis reaction. The preparation method provided by the invention has the advantages of simplicity and convenience, easiness in operation, low environmental pollution, stable process, good repeatability, high product yield, high product purity and few impurities.

Preparation method of pidotimod

The invention provides doxercalciferol derivatives and preparation method thereof. The doxercalciferol derivatives has the following molecular structural formula: FORMULA (referring to the specification), wherein R group is selected from FORMULAE (referring to the specification). In the invention, doxercalciferol is used as a starting material and is sequentially subjected to bromination reaction,hydrolysis reaction and etherification reaction to obtain the doxercalciferol derivatives. Compared with doxercalciferol, the doxercalciferol derivatives is greatly improved in water solubility and more beneficial for clinical use of drugs.

Doxercalciferol derivatives and preparation method thereof

The invention discloses a synthesis method of pidotimod. According to the synthesis method, L-thiazolidine-4-carboxylate with a protected carboxyl R group or L-thiazolidine-4-carboxylic acid and pyroglutamic acid with protected nitrogen R1 carry out condensation reactions in the presence of an enzyme catalyst to form a target compound namely pidotimod represented by the formula III. Enzymes are taken as the catalyst, the conventional oxazolone racemate generation mechanism is avoided totally; the reaction mechanism is completely different from a conventional synthesis and activation principleand mechanism, the racemization problem is radically solved, the feed ratio is greatly reduced, moreover, the yield and product quality are largely improved, and the synthesis method is suitable for industrial production.

Synthesis method of pidotimod

The invention provides a doxercalciferol analogue and a preparation method thereof. A molecular structural formula is as follows: the formula is shown in the description, wherein R is selected from formulas in the description. According to the doxercalciferol analogue, doxercalciferol is used as a starting material and is subjected to hydroxyl protection reaction, bromination reaction, hydrolysisreaction, etherification reaction and hydroxyl deprotection reaction in sequence to obtain the doxercalciferol analogue; compared with the doxercalciferol, the doxercalciferol analogue has the advantages that the water solubility is relatively greatly improved and clinical application of medicines is facilitated.

Doxercalciferol analogue and preparation method thereof

The invention provides a vitamin D3 compound. A structural formula of the vitamin D3 compound is shown in the following formula (the formula is shown in the description). The water solubility of the vitamin D3 compound improved and the vitamin D3 compound is more beneficial to clinic use of drugs.

Vitamin D3 compound and preparation method thereof

The invention provides a method for synthesizing a doxercalciferol analog WXFQ-65 The method comprises the following steps: performing halogenation reaction on doxercalciferol in an organic solvent by using an excessive amount of a halogenating agent, adding a hydrolysis reagent to perform a hydrolysis reaction under an acid condition, and adding a recrystallization reagent for recrystallization, thereby obtaining the doxercalciferol analog WXFQ-65 According to the method, the excessive amount of the halogenating agent is adopted to perform halogenations on the doxercalciferol, and a final product is prepared through hydrolysis and recrystallization, so that a highly toxic raw material, namely, selenium dioxide, is not adopted for oxidation, and in addition, the product is good in optical activity, short in synthesis step, gentle in condition, environmentally friendly in synthesis process and applicable to industrial production, and the finally prepared doxercalciferol analog WXFQ-65 is relatively good in water solubility, and the absorption rate of the doxercalciferol analog WXFQ-65 in human bodies can be increased

Method for synthesizing doxercalciferol analog WXFQ-65

The invention provides a synthesis method of pidotimod disclosed as Formula (1) The synthesis method comprises the following steps: (1) carrying out condensation reaction on thioproline and cyprolidol under the actions of a catalyst and a condensation reaction solvent to obtain an intermediate I; (2) carrying out condensation reaction on the intermediate I and pyroglutamic acid under the actions of a catalyst and a condensation reaction solvent to obtain an intermediate II; and (3) dropwisely adding an acidic material into the intermediate II, and carrying out degreasing reaction in a degreasing reaction solvent The synthesis method avoids using thionyl chloride, pentachlorophenol and other toxic reagents, and thus, has favorable environment friendliness The method does not need strong alkali high-temperature esterolysis, so the synthesis process is milder The intermediate I and intermediate II can absorb ultraviolet light, so that the whole synthesis progress can be monitored conveniently In addition, the optical purity of the pidotimod prepared by the synthesis method is higher

The invention provides a doxercalciferol analogue WXFQ-65 and a synthetic method thereof. The synthetic method comprises the steps of carrying out halogenating reaction on vitamin D2 in an organic solvent by virtue of an excess amount of halogenating reagents, adding a hydrolysis reagent to generate hydrolysis reaction under an acidic condition, and carrying out chromatographic separation, so as to obtain the doxercalciferol analogue WXFQ-65. According to the synthetic method, the excess amount of halogenating reagents such as NBS, Br2 or Cl2 are utilized for carrying out halogenating reaction on vitamin D2, hydrolysis is then carried out, and a chromatographic column is utilized for carrying out chromatographic separation, so that the use of selenium dioxide for oxidization is avoided, the optical activity of the product is good, steps of a synthetic process are short, conditions are mild, the synthetic process is environment-friendly and applicable to industrial production, and the doxercalciferol analogue WXFQ-65 has relatively good water solubility and is easy to absorb.

Doxercalciferol analogue WXFQ-65 and synthetic method thereof

The invention provides a mitiglinide-levocarnitine coupling compound (I) and a preparation method thereof. The preparation method comprises the following steps: firstly adding mitiglinide and levocarnitine into an organic solvent in a certain proportion, adequately mixing to obtain turbid liquid, and adding a catalyst into the turbid liquid in a certain proportion to generate esterification coupling reaction; carrying out suction filtration, so as to obtain a filter cake; and washing the filter cake with the organic solvent, and adding a recrystallization reagent for recrystallization, so as to obtain the mitiglinide-levocarnitine coupling compound (I). Animal experiments prove that the synergetic effect of pharmacological activities of mitiglinide and levocarnitine is realized by virtue of the mitiglinide-levocarnitine coupling compound (1), the content of blood sugar can be reduced, and the diabetic retinopathy can be effectively inhibited.

Mitiglinide-levocarnitine coupling compound (I) and preparation method thereof

The invention provides a method for resolving medetomidine. The method comprises the following steps: (1) adding medetomidine, an acid and a catalyst to an organic solvent to produce medetomidine amide; (2): carrying out asymmetric hydrolysis of medetomidine amide under the weak acid condition by using enzyme Novozym435 as a resolving agent, and extracting dexmedetomidine with an extractant. In the invention, camphorsulfonic acid is prevented from being used as a chiral agent, and a novel method for resolving medetomidine is provided to prepare the dexmedetomidine. The method has the advantages of easiness in operation, mild conditions, high yield, good optical activity and the like.

Method for resolving medetomidine

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