Stable isotope deuterium-labeled danofloxacin and synthetic method thereof
Technical Field
The invention relates to the field of isotope labeling, in particular to stable isotope deuterium labeled danofloxacin and a synthetic method thereof.
Background
Danofloxacin mesylate was first introduced by the company pfeiri, usa and was marketed in mexico and other countries in 1990 under the trade name Advocin. Approved as second-class new veterinary drugs in China in 2001, is mainly used for treating respiratory tract infection of livestock and poultry, and has the characteristics of wide antibacterial spectrum, strong antibacterial activity, no drug resistance, small adverse reaction, high oral bioavailability, convenient use and the like.
For quantitative analysis of danofloxacin, stable Isotope Dilution Mass Spectrometry (IDMS) is mainly used at present. IDMS uses a stable isotope labeled compound with the same molecular structure as a detected substance as an internal standard substance, uses a high-resolution liquid chromatography-mass spectrometer (LC-MS) to detect, measures the ratio of ions with corresponding mass numbers through a mass spectrometer and compares the ratio with a standard ratio to achieve the purpose of accurate quantification. The isotope internal standard can effectively eliminate the recovery rate difference of the sample in the chemical and physical pretreatment steps, thereby avoiding the deviation of the loss in the sample treatment process to the detection result.
At present, the stable isotope deuterium-labeled danofloxacin product is mainly from abroad, no company is independently researched and developed and produced at home, and a synthetic method of the stable isotope deuterium-labeled danofloxacin is not reported. Therefore, there is a need to provide a method for synthesizing stable isotope labeled danofloxacin.
Disclosure of Invention
The invention aims to solve the technical problem of providing stable isotope deuterium labeled danofloxacin and a synthesis method thereof, which can obtain stable isotope labeled danofloxacin with very high chemical purity and isotope abundance, and can be used as a stable isotope internal standard for IDMS (ion dispersive mass spectrometry) and quantitatively analyze danofloxacin.
The technical scheme adopted by the invention for solving the technical problems is to provide a synthetic method of stable isotope deuterium-labeled danofloxacin, which comprises the following steps: s1: deuterated iodomethane and (1S, 4S) -2-BOC-2, 5-diazabicyclo [2.2.1] heptane are reacted to introduce a stable isotope deuterium-labeled methyl; s2: removing BOC protecting group; s3: and (3) reacting the product obtained in the step (S2) with 1-cyclopropyl-6, 7-difluoro-1, 4-dihydro-4-oxoquinoline-3-carboxylic acid to obtain the danofloxacin marked by the deuterium as the stable isotope.
Further, the synthesis method according to claim 1, wherein the step S1 is as follows: dissolving (1S, 4S) -2-BOC-2, 5-diazabicyclo [2.2.1] heptane in tetrahydrofuran, preserving heat at 0-5 ℃ for 5-10 minutes, adding 60 wt% sodium hydride in batches, keeping the temperature at 0-5 ℃, dropwise adding deuterated iodomethane at the speed of 1-2 drops/second, preserving heat at 0-5 ℃ for reacting for 30-60 minutes, recovering to room temperature, filtering, and performing decompression spin-drying on the solvent to obtain the product.
Further, the molar ratio of the (1S, 4S) -2-BOC-2, 5-diazabicyclo [2.2.1] heptane, sodium hydride and deuterated iodomethane is 1: 2-3: 2 to 3.
Further, the step S2 process is as follows: and (3) dissolving the product obtained in the step (S1) in 1, 4-dioxane, preserving heat for 5-10 minutes at 0-5 ℃, dropwise adding 36-38 wt% hydrochloric acid at the speed of 1-2 drops/second, keeping the temperature at 0-5 ℃, then reacting for 30-60 minutes at the temperature of 25-30 ℃, and performing decompression and spin-drying on the solvent to obtain the product.
Further, the molar ratio of the product of step S1 to hydrochloric acid is 1: 0.01 to 0.05.
Further, the step S3 process is as follows: and (3) dissolving the product obtained in the step (S2), 1-cyclopropyl-6, 7-difluoro-1, 4-dihydro-4-oxyquinoline-3-formic acid and 1, 8-diazabicyclo [5.4.0] undec-7-ene in pyridine, reacting for 8-12 hours at the temperature of 95-105 ℃, and performing column chromatography separation and purification after the solvent is dried in a rotary manner under reduced pressure to obtain the stable isotope deuterium-labeled danofloxacin.
Further, the product of step S2, the molar ratio of 1-cyclopropyl-6, 7-difluoro-1, 4-dihydro-4-oxoquinoline-3-carboxylic acid and 1, 8-diazabicyclo [5.4.0] undec-7-ene is 1: 1-1.5: 3 to 4.
Further, the present invention provides a stable isotope deuterium-labeled danofloxacin prepared by the above synthesis method, which has a molecular structure:
the invention has the following beneficial effects: the invention provides stable isotope deuterium labeled danofloxacin and a synthesis method thereof, which can be used as a standard reagent for quantitatively detecting danofloxacin and have the following advantages:
(1) the synthesis process has the advantages of cheap and easily-obtained raw materials, mild reaction conditions, short route, no shedding of stable isotope deuterium, and capability of obtaining a product marked by the stable isotope deuterium at a specific position.
(2) The product of the invention is easy to separate and purify, has high yield, has chemical purity and stable isotope abundance of more than 99 percent, and can fully meet the requirement of standard reagent for quantitatively detecting the danofloxacin.
(3) The invention has high use value and good economical efficiency.
Drawings
FIG. 1 shows stable isotope deuterium labeled danofloxacin-D obtained in example 1 of the present invention3Mass spectrum of (2).
FIG. 2 shows the stable isotope deuterium-labeled danofloxacin-D obtained in example 1 of the present invention3Nuclear magnetic resonance hydrogen spectrum of (a).
FIG. 3 shows the stable isotope deuterium-labeled danofloxacin-D obtained in example 1 of the present invention3The high performance liquid chromatogram of (1).
Detailed Description
The invention is further described in the following examples, which should not be construed as limiting the invention.
Example 1
The synthesis of stable isotope deuterium labeled danofloxacin was as follows:
s1.2.5g of (1S, 4S) -2-BOC-2, 5-diazabicyclo [2.2.1] heptane is dissolved in 300mL of tetrahydrofuran, the temperature is kept at 0-5 ℃ for 5 minutes, 1.45g of 60 wt% sodium hydride is added in batches, the temperature is kept at 0-5 ℃, 2.0mL of deuterated iodomethane is dropwise added at the speed of 1-2 drops/second, then the temperature is kept at 0-5 ℃ for reaction for 40 minutes, the reaction is carried out after the reaction is carried out for returning to the room temperature, the filtration is carried out, and the solvent is dried in a rotary manner under reduced pressure, so that a product is obtained;
s2, dissolving the product obtained in the step S1 in 100mL of 1, 4-dioxane, preserving heat at 0-5 ℃ for 10 minutes, dropwise adding 10mL of 36-38 wt% hydrochloric acid at a speed of 1-2 drops/second, keeping the temperature at 0-5 ℃, then reacting at 25-30 ℃ for 60 minutes, and performing reduced pressure spin drying on the solvent to obtain a product;
s3, dissolving the product obtained in the step S2, 4.5g of 1-cyclopropyl-6, 7-difluoro-1, 4-dihydro-4-oxoquinoline-3-formic acid and 7.0g of 1, 8-diazabicyclo [5.4.0] undec-7-ene in 30mL of pyridine, reacting at the temperature of 95-105 ℃ for 10 hours, performing column chromatography separation and purification by using a dichloromethane/methanol/triethylamine system as an eluent after the solvent is dried in a decompression mode to obtain the danofloxacin marked by the stable isotope deuterium, wherein the chemical purity and the stable isotope abundance of the obtained product are more than 99%.
The mass spectrum of the product obtained in this example obtained by LC-MS is shown in fig. 1, and as can be seen from fig. 1, the molecular ion peak M/z is 361.1([ M + H) ("M + H") (M + H)]+)。
The product obtained in this example was treated with DMSO-D6As a solvent, the NMR spectrum shown in FIG. 2 was obtained by Bruke-400M NMR, and as can be seen from FIG. 2, no absorption peak was observed at the chemical shift of-2.32 ppm.
The combination of mass spectrum and nuclear magnetic data shows that the product structure is danofloxacin-D3。
Meanwhile, the product sample obtained in this example was dissolved in methanol, and the ratio of acetonitrile: 20mM phosphoric acid solution ═ 20: 80 as mobile phase, passing through a liquid phase column (Athena C18-WP 4.6 × 250mm, 5um) with column temperature of 30 deg.C at flow rate of 1.0mL/min, and passing through DAD detector to obtain danofloxacin-D3As shown in fig. 3, it can be seen from fig. 3 that the sample purity of (a) is 99% or more.
Example 2
The synthesis of stable isotope deuterium labeled danofloxacin was as follows:
s1.3.0g of (1S, 4S) -2-BOC-2, 5-diazabicyclo [2.2.1] heptane is dissolved in 400mL of tetrahydrofuran, the temperature is kept at 0-5 ℃ for 5 minutes, 1.6g of 60 wt% sodium hydride is added in batches, the temperature is kept at 0-5 ℃, 2.5mL of deuterated iodomethane is dropwise added at the speed of 1-2 drops/second, then the temperature is kept at 0-5 ℃ for reaction for 60 minutes, the reaction is carried out after the reaction is carried out for returning to the room temperature, the filtration is carried out, and the solvent is dried in a rotary manner under reduced pressure, so that a product is obtained;
s2, dissolving the product obtained in the step S1 in 100mL of 1, 4-dioxane, preserving heat at 0-5 ℃ for 10 minutes, dropwise adding 20mL of 36-38 wt% hydrochloric acid at a speed of 1-2 drops/second, keeping the temperature at 0-5 ℃, then reacting at 25-30 ℃ for 60 minutes, and performing reduced pressure spin drying on the solvent to obtain a product;
s3, dissolving the product obtained in the step S2, 5.0g of 1-cyclopropyl-6, 7-difluoro-1, 4-dihydro-4-oxoquinoline-3-formic acid and 7.6g of 1, 8-diazabicyclo [5.4.0] undec-7-ene in 50mL of pyridine, reacting at the temperature of 95-105 ℃ for 12 hours, performing column chromatography separation and purification by using a dichloromethane/methanol/triethylamine system as an eluent after the solvent is dried in a decompression mode to obtain the danofloxacin marked by the stable isotope deuterium, wherein the chemical purity and the stable isotope abundance of the obtained product are more than 99%.
Although the present invention has been described with respect to the preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.