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A technology of criborole and intermediates, which is applied in chemical instruments and methods, compounds containing elements of Group 3/13 of the periodic table, organic chemistry, etc., can solve the problems of expensive starting materials, and achieve cheap raw materials. , low price, good effect of industrial production
Inactive Publication Date: 2018-12-14
WUHAN POLYTECHNIC UNIVERSITY
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This method has used organic palladium catalyst and bis-linked pinacol borate, and starting material is expensive
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preparation example Construction
[0027] The invention provides a preparation method of a crisborole intermediate, the crisborole intermediate has a structure shown in formula VI,
[0028] This preparation method comprises the steps:
[0029] (1) In the presence of the first organic solvent and the first base, the compound shown in formula I is contacted with benzyl halide to obtain the compound shown in formula II;
[0030]
[0031] (2) In the presence of a second solvent, the compound represented by the formula II and the alkali metal borohydride are subjected to a contact reaction to obtain the compound represented by the formula III;
[0032]
[0033] (3) In the presence of the third organic solvent and the second base, the compound shown in the formula III and the compound a are subjected to a contact reaction to obtain the compound shown in the formula IV; or in the presence of the third organic solvent and the first catalyst , contacting the compound shown in formula III and dihydropyran to obtai...
Embodiment
[0051] Such as figure 2 As shown, the present embodiment provides a preparation method of crisborole intermediate, and the specific preparation method is as follows:
[0052] (1) Preparation of 5-benzyloxy-2-bromo-benzaldehyde (compound shown in formula Ⅱ)
[0053] 201g (1mol) 2-bromo-5-hydroxy-benzaldehyde (compound shown in formula I), 1000ml acetone, 276g (1.1mol) of potassium carbonate were added to the reaction kettle, and 152g (1.2mol) of benzyl chloride was added under stirring , refluxed for 10h, recovered the solvent, added 1000ml of water, made a slurry, filtered, and dried under reduced pressure to obtain 279g of solids, with a yield of 96%;
[0054] (2) Preparation of 5-benzyloxy-2-bromo-benzyl alcohol (compound shown in formula III)
[0055] Add 145g (0.5mol) of 5-benzyloxy-2-bromo-benzaldehyde and 2000ml of methanol into the reaction kettle, add 18.9g (1mol) of sodium borohydride in batches, and continue stirring at 25°C for 4h until the raw material After th...
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Abstract
The invention discloses a preparation method of a Crisaborole intermediate. The Crisaborole intermediate has a structure shown as the formula VI. The preparation method comprises the following steps:performing a contact reaction on a compound shown as the formula I and benzyl halide, so as to form a compound shown as the formula II; performing a contact reaction on the compound shown as the formula II and alkali metal borohydride, so as to obtain a compound shown as the formula III; performing a contact reaction on the compound shown as the formula III and a compound a, or performing a contact reaction on the compound shown as the formula III and dihydropyran, so as to obtain a compound shown as the formula IV, wherein the compound a is trimethylchlorosilane, tert-butyldimethylsilyl chloride and chloromethyl methyl ether; performing a contact reaction on the compound shown as the formula IV and an isopropylmagnesium chloride solution; adding an obtained solution into a compound b, performing a contact reaction on the mixture and fourth organic solvent mixed liquor and adding hydrochloric acid into the mixture for contact reaction, so as to obtain a compound shown as the formula V,wherein the compound b is 2-alkoxy-4, 4, 5, 5-tetramethyl-1, 3, 2-dioxaborolane, triisopropyl borate or trimethyl borate; performing a hydrogenation reaction on the compound shown as the formula V toobtain a compound shown as the formula VI.
Description
technical field [0001] The invention belongs to the technical field of pharmacy, and more specifically, relates to a preparation method of a crisborole intermediate. Background technique [0002] Eczema is an allergic inflammatory skin disease caused by a variety of internal and external factors. It is characterized by symmetrical distribution of skin lesions, polymorphic lesions, severe itching, tendency to exudate, and repeated attacks. The disease is lingering and difficult to heal, and the clinical treatment is difficult, which has a great impact on the physical and mental health of patients. [0003] At present, Western medicine is mainly based on symptomatic treatment such as antihistamines, glucocorticoids, and astringent and protective preparations. Although these drugs can control symptoms, they are prone to relapse after drug withdrawal, and long-term, repeated, and large-scale use can cause Children with local telangiectasia, skin pigmentation and other adverse r...
Claims
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