CN109384753B - Synthetic method of 2-phenyl-3-methylbenzofuran compound - Google Patents

Synthetic method of 2-phenyl-3-methylbenzofuran compound Download PDF

Info

Publication number
CN109384753B
CN109384753B CN201710670385.6A CN201710670385A CN109384753B CN 109384753 B CN109384753 B CN 109384753B CN 201710670385 A CN201710670385 A CN 201710670385A CN 109384753 B CN109384753 B CN 109384753B
Authority
CN
China
Prior art keywords
phenyl
methylbenzofuran
reaction
ethyl acetate
hexane
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201710670385.6A
Other languages
Chinese (zh)
Other versions
CN109384753A (en
Inventor
刘永祥
程卯生
汤迎湛
江崇国
肖建勇
林斌
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Shenyang Pharmaceutical University
Original Assignee
Shenyang Pharmaceutical University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Shenyang Pharmaceutical University filed Critical Shenyang Pharmaceutical University
Priority to CN201710670385.6A priority Critical patent/CN109384753B/en
Publication of CN109384753A publication Critical patent/CN109384753A/en
Application granted granted Critical
Publication of CN109384753B publication Critical patent/CN109384753B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07D—HETEROCYCLIC COMPOUNDS
    • C07D307/00—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom
    • C07D307/77—Heterocyclic compounds containing five-membered rings having one oxygen atom as the only ring hetero atom ortho- or peri-condensed with carbocyclic rings or ring systems
    • C07D307/78—Benzo [b] furans; Hydrogenated benzo [b] furans
    • C07D307/79—Benzo [b] furans; Hydrogenated benzo [b] furans with only hydrogen atoms, hydrocarbon or substituted hydrocarbon radicals, directly attached to carbon atoms of the hetero ring
    • C07D307/80—Radicals substituted by oxygen atoms

Abstract

The invention belongs to the technical field of pharmaceutical chemistry, and provides a 2-phenylA method for synthesizing a (E) -3-methylbenzofuran compound. The reaction general formula is shown as follows, the reaction substrate of the method is different substituted 3-benzofuran methyl phenyl ether, and the reaction is promoted by stirring and heating under the conditions of no catalyst and no solvent. The reaction can be rearranged to generate a series of 2-phenyl-3-methylbenzofuran compounds, and the method has the characteristics of simple operation, wide application range, less by-products, high yield and green reaction.

Description

Synthetic method of 2-phenyl-3-methylbenzofuran compound
Technical Field
The invention belongs to the technical field of medicinal chemistry, and relates to a synthetic method of a 2-phenyl-3-methylbenzofuran compound. In particular to a method for generating 2-phenyl-3-methyl benzofuran compounds by rearranging 3-benzofuran methyl phenyl ethers with specific substitution under the condition of no catalyst and no solvent.
Background
The 2-phenyl-3-methylbenzofuran is a natural product which is separated from plants and has various structures and various activities, attracts the attention of many scientists because of wide biological activity, and is a lead compound which can be used for drug development. Various natural products with 2-phenyl-3-methylbenzofuran as a framework have various biological activities and pharmacological effects, such as antibacterial activity (J.Nat.Prod.2006,69, 121-19-124.), antioxidant activity (biosci.Biotechnol.biochem.2001,65, 1402-1405), antitumor activity (chem.Commun.2009,14,1879-1881.), antidiabetic activity (bioorg.Med.chem.Lett.2010,20, 5398-5401-1303-J.Nat.prod.2014, 77, 1297-1303-A). Therefore, the 2-phenyl-3-methylbenzofuran compound has important research significance in the aspects of biological activity and full-synthetic application of medicines or natural products. The methods reported to date for the synthesis of 2-phenyl-3-methylbenzofurans are mainly achieved by catalytic coupling of expensive metal catalysts.
In 2004, the Gillmore topic group discovered a Pd-mediated process2(dba)3The substituted 2-phenyl-3-methylbenzofuran compound can be synthesized by constructing an intramolecular C-O bond through catalysis, and the yield is about 80%. However, this method requires the use of an expensive catalyst (org. Lett.2004,6, 4755-.
Figure BDA0001372921030000011
In 2004, Naito topic group found that trifluoroacetyl triflate and 4-dimethylaminopyridine catalyzed oxime ether compounds can be acylated and rearranged at 0 ℃ for 1.5-5 hours to obtain substituted 2-phenyl-3-methylbenzofuran compounds, and the yield is 15-99%. However, this process also has the disadvantage of requiring the use of expensive trifluoroacetyl triflate as catalyst (org. Lett.2004,6, 1761-1763.).
Figure BDA0001372921030000021
In 2006, the Sanz project group reported a method for synthesizing 2-phenyl-3-methylbenzofuran compounds. Cyclizing the product with carboxylic ester through lithium halogen exchange and benzyl methylene lithiation reaction, and dehydrating under the catalysis of indium chloride to obtain the substituted 2-phenyl-3-methylbenzofuran compound with the yield of 35-73% (J.Org.chem.2006,71, 4024-.
Figure BDA0001372921030000022
In 2011, 2-phenyl-3-methylbenzofuran compounds are obtained by the Jumbam project group through the cyclization reaction of 2-acetyl phenyl benzoate in tetrahydrofuran under the catalysis of titanium trichloride or titanium tetrachloride for 48 hours, and the yield is between 65 and 76 percent (Bull. chem. Soc. Ethiop.2011,25, 157-160.).
Figure BDA0001372921030000023
In 2015, Chung project group obtained 40% yield of 2-phenyl-3-methylbenzofuran compounds by coupling reaction of 3-methylbenzofuran and iodobenzene under catalysis of palladium acetate and silver carbonate (chem.Commun.,2015,51, 14543-14546.).
Figure BDA0001372921030000024
In 2015, the Li group obtained 2-phenyl-3-methylbenzofuran compounds (J.Org.chem.2015,80,10686-10693) by rhodium-catalyzed C-H activation of N-phenoxyacetamide.
Figure BDA0001372921030000025
In summary, natural products of 2-phenyl-3-methylbenzofuran have various structures, have various biological activities, and have very important functions in many aspects, and known reaction conditions for synthesizing 2-phenyl-3-methylbenzofuran analogues require expensive catalysts, and the solvents pollute the environment. According to the atom economy principle of the reaction, the most ideal, economical and green reaction should avoid the use of expensive catalysts and environmentally-polluting solvents and reduce the production of environmentally-unfriendly by-products. However, no such process is known in the art which does not require a catalyst or solvent.
Disclosure of Invention
The technical problem solved by the invention is to overcome the defects of expensive catalyst and serious environmental pollution in the prior art, and provide a novel method for synthesizing the 2-phenyl-3-methylbenzofuran compound by taking the 3-benzofuran methyl phenyl ether compound as a substrate, not requiring a catalyst and a solvent, and adding silica gel as an additive, so that the reaction temperature can be reduced, the reaction yield can be improved, and the 2-phenyl-3-methylbenzofuran compound can be synthesized through a rearrangement reaction.
The invention is realized by the following technical scheme:
the method comprises the following steps of carrying out mitsunobu reaction on a 3-benzofuran methanol compound and a phenol compound under the condition of no catalyst and no solvent heating to prepare 3-benzofuran methyl phenyl ether, and carrying out rearrangement on the 3-benzofuran methyl phenyl ether to obtain the 2-phenyl-3-methylbenzofuran compound. The chemical reaction formula is shown as follows:
Figure BDA0001372921030000031
wherein R is1，R2Is hydrogen, benzyloxy, C1-C4An alkoxy group.
The preparation method of the invention comprises the following steps:
1. charging of
Adding a 3-benzofuran methyl phenyl ether substrate into a round-bottom flask, adding a reaction medium with the molar volume dosage of 1-10 times that of the substrate, adding silica gel with the dosage of 1-3 times of the weight ratio, and evaporating the medium by a rotary evaporator. The reaction medium is as follows: dichloromethane, ethyl acetate, chloroform, acetone, tetrahydrofuran, preferably: dichloromethane in an amount of: 1 to 10 times, preferably 5 times the molar volume of the substrate. 2. Reaction of
Stirring the mixture for reaction at the temperature of 120-160 ℃, wherein the reaction time is 3-5h, and detecting the reaction process by thin layer chromatography. The developing agent for thin-layer chromatography is petroleum ether, ethyl acetate, n-hexane, methanol, chloroform, dichloromethane, acetone, tetrahydrofuran, water or a mixture of two or three of the above, wherein petroleum ether/ethyl acetate (v/v: 50/1-2/1) or n-hexane/ethyl acetate (v/v: 50/1-2/1) or petroleum ether/n-hexane/ethyl acetate (v/v/v: 25/25/1-1/1/1) is preferred
3. Post-treatment of the reaction solution
And (3) directly carrying out column chromatography separation and purification on the cooled reactant and a reaction mixture by using silica gel to obtain a target product, wherein the developing agent system is as follows: petroleum ether, ethyl acetate, n-hexane, methanol, chloroform, dichloromethane, acetone, tetrahydrofuran, water or a mixture of two or three of them, wherein a petroleum ether/ethyl acetate (v/v: 50/1-2/1) or n-hexane/ethyl acetate (v/v: 50/1-2/1) system or a petroleum ether/n-hexane/ethyl acetate (v/v/v: 25/25/1-1/1/1) system is preferable.
The invention has the advantages that 2-phenyl-3-methyl benzofuran compounds can be generated from 3-benzofuran methyl phenyl ether without heating a catalyst and a solvent, the reaction application range is wider, the substrate is cheap and easy to obtain, and the reaction operation is simple and convenient. Compared with the synthesis method of the 2-phenyl-3-methylbenzofuran compound in the prior art, the method conforms to the concept of green chemistry and also ensures higher reaction yield.
Detailed Description
The advantages and the preparation of the present invention will be better understood in connection with the following examples, which are intended to illustrate, but not to limit the scope of the invention.
Example 1
Dissolving a substrate 1(1mmol) in mesitylene (2mL), heating the reaction mixture to 180 ℃, stirring and reacting for 4 hours, and separating by using a flash column chromatography method after the reaction is finished to obtain a target product a with the yield of 35%. The reaction equation is as follows:
Figure BDA0001372921030000041
spectral data for product a were:1H NMR(600MHz,CDCl3)δ7.46(d,J＝7.4Hz,2H),7.42(d,J＝7.1Hz,2H),7.39(t,J＝8.4Hz,5H),7.33(m,2H),7.25(m,5H),7.08(d,J＝2.2Hz,1H),6.97(dd,J＝8.5,2.2Hz,1H),6.32(d,J＝2.2Hz,1H),6.29(d,J＝2.2Hz,1H),5.93(s,1H),5.12(s,2H),5.04(s,2H),5.02(s,2H),2.09(s,3H)；13C NMR(150MHz,CDCl3)δ161.7,158.6,157.3,156.7,155.6,143.9,137.1,136.8,136.7,128.8,128.7,128.6,128.3,128.1,127.8,127.7,127.6,127.1,124.1,119.7,115.8,112.2,100.4,97.3,94.7,94.2,70.8,70.6,70.30,9.26；HRMS(ESI):m/z:Calcd.for C36H30O5[M+H]+543.2166,Found 543.2173。
example 2
Substrate 1(1mmol) was dissolved in toluene (2mL) and ZnCl was added2(0.2mmol,27mg) of Triton, andheating the reaction mixture to 140 ℃, stirring and reacting for 4 hours, and separating by using a flash column chromatography method after the reaction is finished to obtain a target product a with the yield of 40%. The reaction equation is as follows:
Figure BDA0001372921030000051
spectral data for product a were:1H NMR(600MHz,CDCl3)δ7.46(d,J＝7.4Hz,2H),7.42(d,J＝7.1Hz,2H),7.39(t,J＝8.4Hz,5H),7.33(m,2H),7.25(m,5H),7.08(d,J＝2.2Hz,1H),6.97(dd,J＝8.5,2.2Hz,1H),6.32(d,J＝2.2Hz,1H),6.29(d,J＝2.2Hz,1H),5.93(s,1H),5.12(s,2H),5.04(s,2H),5.02(s,2H),2.09(s,3H)；13C NMR(150MHz,CDCl3)δ161.7,158.6,157.3,156.7,155.6,143.9,137.1,136.8,136.7,128.8,128.7,128.6,128.3,128.1,127.8,127.7,127.6,127.1,124.1,119.7,115.8,112.2,100.4,97.3,94.7,94.2,70.8,70.6,70.30,9.26；HRMS(ESI):m/z:Calcd.for C36H30O5[M+H]+543.2166,Found 543.2173。
example 3
Dissolving the substrate 1(1mmol) in dichloromethane (2mL), adding silica gel (1g), distilling under reduced pressure to evaporate dichloromethane to dryness, heating the reaction mixture to 140 ℃, stirring for reaction for 4 hours, and separating by using a flash column chromatography method after the reaction is finished to obtain the target product a with the yield of 75%. The reaction equation is as follows:
Figure BDA0001372921030000052
spectral data for product a were:1H NMR(600MHz,CDCl3)δ7.46(d,J＝7.4Hz,2H),7.42(d,J＝7.1Hz,2H),7.39(t,J＝8.4Hz,5H),7.33(m,2H),7.25(m,5H),7.08(d,J＝2.2Hz,1H),6.97(dd,J＝8.5,2.2Hz,1H),6.32(d,J＝2.2Hz,1H),6.29(d,J＝2.2Hz,1H),5.93(s,1H),5.12(s,2H),5.04(s,2H),5.02(s,2H),2.09(s,3H)；13C NMR(150MHz,CDCl3)δ161.7,158.6,157.3,156.7,155.6,143.9,137.1,136.8,136.7,128.8,128.7,128.6,128.3,128.1,127.8,127.7,127.6,127.1,124.1,119.7,115.8,112.2,100.4,97.3,94.7,94.2,70.8,70.6,70.30,9.26；HRMS(ESI):m/z:Calcd.for C36H30O5[M+H]+543.2166,Found 543.2173。
example 4
The reaction substrate 1 was changed to the reaction substrate 2, and the same procedure as in example 3 was repeated to give the objective compound b in a reaction yield of 63%. The reaction equation is as follows:
Figure BDA0001372921030000061
spectral data for product b were:1H NMR(600MHz,CDCl3)δ7.47(t,J＝8.3Hz,4H),7.42(m,5H),7.35(m,3H),7.09(d,J＝2.1Hz,1H),7.01(dd,J＝8.5,2.1Hz,1H),6.96(s,1H),6.69(d,J＝2.5Hz,1H),6.66(dd,J＝8.5,2.5Hz,1H),5.14(s,2H),5.10(s,2H),2.34(s,3H)；13C NMR(150MHz,CDCl3)δ155.5,136.9,136.8,129.9,128.8,128.2,128.1,127.7,126.6,119.6,112.6,112.0,110.0,108.0,103.0,97.2,70.8,70.2,9.3；HRMS(ESI):m/z:Calcd.for C29H24O4[M+H]+437.1747,Found 437.1750。
example 5
The reaction substrate 1 was changed to the reaction substrate 3, and the same procedure as in example 3 was repeated to give the objective compound c in a reaction yield of 79%. The reaction equation is as follows:
Figure BDA0001372921030000062
spectral data for product c were:1H NMR(600MHz,CDCl3)δ7.61(s,1H),7.53(d,J＝8.5Hz,1H),7.47(d,J＝7.4Hz,2H),7.41(t,J＝7.4Hz,2H),7.35(d,J＝7.4Hz,1H),7.22(t,J＝8.2Hz,1H),7.11(d,J＝2.2Hz,1H),7.00(dd,J＝8.0,2.2Hz,1H),6.63(dd,J＝8.0,2.1Hz,1H),6.58(t,J＝2.1Hz,1H),6.56(dd,J＝8.2,2.2Hz,1H),5.15(d,J＝0.6Hz,2H),5.12(s,2H),3.80(s,3H)；13C NMR(150MHz,CDCl3)δ161.0,16.0,157.5,156.6,142.5,136.9,130.1,128.8,128.2,127.6,120.5,120.4,116.8,112.8,106.9,109.8,101.5,97.5,70.7,61.4,55.4；HRMS(ESI):m/z:Calcd.for C23H20O4[M+H]+361.1434,Found 361.1439。

Claims (6)

  1. a method for synthesizing 2-phenyl-3-methylbenzofuran compounds is characterized by comprising the following steps: the method comprises the following steps of,
    (1) charging of
    Adding a 3-benzofuran methyl phenyl ether substrate into a reaction medium with the molar volume dosage of 1-10 times of that of the substrate, adding silica gel with the dosage of 1-3 times of that of the substrate by weight ratio, and evaporating the medium by a rotary evaporator;
    (2) reaction of
    Stirring and reacting at the temperature of 120-160 ℃, wherein the reaction time is 3-5h, and detecting the reaction process by thin-layer chromatography;
    (3) post-treatment of the reaction solution
    Directly carrying out column chromatography separation and purification on the cooled reactant by using silica gel to obtain a 2-phenyl-3-methylbenzofuran compound;
    Figure DEST_PATH_IMAGE002
    R1，R2is hydrogen, benzyloxy, C1-C4An alkoxy group.
  2. 2. The method for synthesizing a 2-phenyl-3-methylbenzofuran compound according to claim 1, characterized in that: the reaction medium in the step (1) is as follows: dichloromethane, ethyl acetate, chloroform, acetone and tetrahydrofuran, and the dosage is as follows: 1-10 times of the molar volume of the substrate.
  3. 3. The method for synthesizing a 2-phenyl-3-methylbenzofuran compound according to claim 1, characterized in that: the developing agent of the thin-layer chromatography in the step (2) is petroleum ether, ethyl acetate, n-hexane, methanol, chloroform, dichloromethane, acetone, tetrahydrofuran, water or a mixture of two or three of the petroleum ether, the ethyl acetate, the n-hexane, the methanol, the chloroform, the dichloromethane, the acetone, the tetrahydrofuran and the water.
  4. 4. The method for synthesizing a 2-phenyl-3-methylbenzofuran compound according to claim 1, characterized in that: the developing agent for the thin-layer chromatography in the step (2) is a petroleum ether/ethyl acetate or n-hexane/ethyl acetate developing system with a volume ratio of 50/1-2/1 or a petroleum ether/n-hexane/ethyl acetate with a volume ratio of 25/25/1-1/1/1.
  5. 5. The method for synthesizing a 2-phenyl-3-methylbenzofuran compound according to claim 1, characterized in that: the separation and purification method of the product in the step (3) comprises the following steps: the column chromatography method is directly used for separation and purification, and the developing agent system is as follows: petroleum ether, ethyl acetate, n-hexane, methanol, chloroform, dichloromethane, acetone, tetrahydrofuran, water or their mixture.
  6. 6. The method for synthesizing a 2-phenyl-3-methylbenzofuran compound according to claim 1, characterized in that: and (3) performing column chromatography separation by using a petroleum ether/ethyl acetate or n-hexane/ethyl acetate system with a volume ratio of 50/1-2/1 or a petroleum ether/n-hexane/ethyl acetate system with a volume ratio of 25/25/1-1/1/1.
CN201710670385.6A 2017-08-08 2017-08-08 Synthetic method of 2-phenyl-3-methylbenzofuran compound Active CN109384753B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201710670385.6A CN109384753B (en) 2017-08-08 2017-08-08 Synthetic method of 2-phenyl-3-methylbenzofuran compound

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201710670385.6A CN109384753B (en) 2017-08-08 2017-08-08 Synthetic method of 2-phenyl-3-methylbenzofuran compound

Publications (2)

Publication Number Publication Date
CN109384753A CN109384753A (en) 2019-02-26
CN109384753B true CN109384753B (en) 2021-07-23

Family

ID=65413929

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201710670385.6A Active CN109384753B (en) 2017-08-08 2017-08-08 Synthetic method of 2-phenyl-3-methylbenzofuran compound

Country Status (1)

Country Link
CN (1) CN109384753B (en)

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111592509B (en) * 2020-06-08 2022-11-22 江苏师范大学 Method for synthesizing aryl (3-sulfuryl benzofuran-2-yl) ketone compound by copper catalysis

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103224479A (en) * 2013-04-26 2013-07-31 温州大学 Synthetic method of 2-arylbenzofuran compounds
CN103275043A (en) * 2013-06-09 2013-09-04 中国科学院成都生物研究所 Synthesis method for 2-arylbenzofuran and derivative thereof

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103224479A (en) * 2013-04-26 2013-07-31 温州大学 Synthetic method of 2-arylbenzofuran compounds
CN103275043A (en) * 2013-06-09 2013-09-04 中国科学院成都生物研究所 Synthesis method for 2-arylbenzofuran and derivative thereof

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
New insight into the mechanism of hypervalent iodine oxidation of flavanones;Laszlo Juhasz等;《Tetrahedron》;20021231;第58卷;第4264页第3.1.11节 *

Also Published As

Publication number Publication date
CN109384753A (en) 2019-02-26

Similar Documents

Publication Publication Date Title
Liu et al. Organocatalytic asymmetric reaction of indol-2-yl carbinols with enamides: synthesis of chiral 2-indole-substituted 1, 1-diarylalkanes
Wu et al. Chiral Brønsted acid-catalyzed alkylation of C3-substituted indoles with o-hydroxybenzyl alcohols: highly enantioselective synthesis of diarylindol-2-ylmethanes and evaluation on their cytotoxicity
Tang et al. Highly diastereoselective synthesis of cyclopropane-fused spiro-pseudoindoxyl derivatives through [2+ 1] annulation of 2-ylideneoxindoles and sulfonium bromides
CN111233795A (en) Preparation method and application of chiral gamma-butyrolactone compound and derivative thereof
Meshram et al. Bismuthtriflate-catalyzed Reaction of N-Alkylisatins with Allyltrimethylsilane
CN109384753B (en) Synthetic method of 2-phenyl-3-methylbenzofuran compound
CN108148021B (en) 2-imine (3H) polysubstituted furan or thiophene derivative and synthesis thereof
CN106146334A (en) 2,3-diaryl-2-propargyl amide groups-3-arylamino methyl propionate derivant and its preparation method and application
CN105820174A (en) Polysubstituted thienoindole derivative and preparation method thereof
CN111303096B (en) Synthesis method of polysubstituted 1, 3-dihydronaphtho [2,3-c ] furan derivative
He et al. Synthesis of polysubstituted phenyl acetates via FeCl3-mediated domino reaction of 2-(aryl (piperidin-1-yl) methyl) phenols and 1, 3-diketones
CN113979918A (en) C-3-position five-membered spiro indolone derivative containing all-carbon tetra-substituted olefin structure and preparation and application thereof
CN109942432B (en) Triaryl methanol compound and synthetic method thereof
CN111559993A (en) Preparation method of furan methanol compound
CN111808045B (en) Method for synthesizing chiral seven-element cyclic sulfonamide through organic catalysis
CN111039844A (en) Polysubstituted arylpyrrole compounds
CN104860911A (en) Synthesis method of chiral 3,4-dihydrocoumarin derivative compound
CN109705052B (en) Method for preparing 1, 4-dihydrooxazine
CN114989132B (en) Method for synthesizing spiro compounds through lithium iodide catalysis
CN113214199B (en) Synthetic method of benzofuran-3-oxocarboxylate compound
CN115215783B (en) Propargyl substituted chiral 3-amino-3, 3-disubstituted oxindole compound, and synthetic method and application thereof
CN113234083B (en) Tetrahydroquinoline pyran compound and preparation method and application thereof
CN111018869B (en) Preparation method of chiral fused ring pyrano-dihydropyrrole compound
CN112321401B (en) Method for preparing 2-hydroxyethyl phenyl ketone by catalytic oxidation of heterochroman
CN115160331B (en) Indole oxide spiro allyl substituted chromane skeleton and preparation method thereof

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant