1978-38-7

Usage

Uses

Used in Pharmaceutical Industry:
2-Fluoro-N-methylaniline is used as a key intermediate in the synthesis of various pharmaceutical compounds, particularly muscarinic agonists. Its role in the development of these medications is crucial due to its ability to modulate the muscarinic receptors, which are involved in various physiological processes.
The application of 2-Fluoro-N-methylaniline in the pharmaceutical industry is primarily for the development of drugs that target muscarinic receptors, which play a vital role in the regulation of various bodily functions. By acting as a muscarinic agonist, these drugs can potentially treat a range of conditions, including respiratory disorders, gastrointestinal issues, and certain neurological conditions.

Synthetic route

2-Fluoroaniline (348-54-9) + carbonic acid dimethyl ester (616-38-6) → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
under 760.051 Torr; Reagent/catalyst; Molecular sieve; Reflux; Green chemistry;	99.4%

N-methyl-N-(2-fluorophenyl)formamide (1272654-63-3) → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
With sulfuric acid; water at 80℃; for 5h;	98.4%
With C18H37ClMoNO2P2; hydrogen; sodium triethylborohydride In tetrahydrofuran; toluene at 130℃; under 37503.8 Torr; for 24h; Autoclave; Glovebox;	15 %Chromat.

N-(2-fluorophenyl)methanimine → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
With hydrogen at 120℃; under 7500.75 Torr; for 3h; Reagent/catalyst; Temperature; Pressure;	96.6%

formaldehyd (50-00-0) + 2-Fluoroaniline (348-54-9) → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
Stage #1: formaldehyd; 2-Fluoroaniline With potassium hydroxide In methanol at 85℃; for 2h; Sealed tube; Stage #2: With methanol; sodium tetrahydroborate at 0 - 85℃; for 1h; Reagent/catalyst; Temperature; Sealed tube;	95%
With methanol; sodium tetrahydroborate; sodium at 60℃; for 2h;	65%

2-Fluoroaniline (348-54-9) + methylamine (74-89-5) → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
Stage #1: 2-Fluoroaniline With hydrogenchloride In water for 0.5h; Stage #2: With sodium nitrite In water at -10 - 5℃; for 1.5h; Stage #3: methylamine In water at 50℃; for 2.5h; Temperature;	95%

N-methyl-N-nosyl-o-fluoroaniline (900537-29-3) + mercaptoacetic acid (68-11-1) → 2-(4-nitrophenylthio)acetic acid (3406-75-5) + 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
With 1,8-diazabicyclo[5.4.0]undec-7-ene In acetonitrile at 20℃;	A n/a B 88%

methanol (67-56-1) + 2-Fluoroaniline (348-54-9) → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
With [Cp*Ir(2-(1H-benzo[d]imidazol-2-yl)-1H-benzo[d]imidazole)Cl][Cl]; caesium carbonate at 120℃; for 12h; Schlenk technique;	87%

2-Fluoroaniline (348-54-9) + methyl iodide (74-88-4) → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
Stage #1: 2-Fluoroaniline With n-butyllithium In tetrahydrofuran; hexane at -50 - 20℃; for 1.25h; Stage #2: methyl iodide In tetrahydrofuran; hexane for 5.25h; Further stages.;	80%

N-(2-fluorophenyl)formamide (824-48-6) → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
In tetrahydrofuran; methanol	59%
Stage #1: N-(2-fluorophenyl)formamide With borane In tetrahydrofuran Heating; Stage #2: With hydrogenchloride In methanol; ethanol Further stages.;
With hydrogenchloride; sodium hydroxide; borane In tetrahydrofuran; 1,4-dioxane at 0 - 60℃; for 4h; Under argon gas;

2-Fluoroaniline (348-54-9) → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
Multi-step reaction with 3 steps 1: 93 percent / pyridine / CH2Cl2 / 20 °C 2: 100 percent / CH2Cl2 / 0.17 h / 20 °C 3: 88 percent / 1,8-diazabicyclo[5.4.0]undec-7-ene / acetonitrile / 20 °C View Scheme
Multi-step reaction with 2 steps 1.1: acetic anhydride / 2 h / 50 °C 1.2: 1 h / 20 °C 2.1: borane-THF / tetrahydrofuran / 2 h / 50 °C 2.2: 1 h / 60 °C View Scheme
Multi-step reaction with 3 steps 1: triethylamine / dichloromethane / 3 h / 0 - 20 °C / Large scale 2: sodium hydride / mineral oil; tetrahydrofuran / 4 h / 0 °C / Large scale 3: ammonium hydroxide / water / 5 h / Reflux; Large scale View Scheme
Multi-step reaction with 3 steps 1: toluene / 6 h / 88 - 110 °C 2: potassium carbonate / 4 h / 130 °C / 3000.3 - 4500.45 Torr / Autoclave 3: sulfuric acid; water / 5 h / 80 °C View Scheme

N-(2-fluorophenyl)-4-nitrobenzenesulfonamide (1766-57-0) → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: 100 percent / CH2Cl2 / 0.17 h / 20 °C 2: 88 percent / 1,8-diazabicyclo[5.4.0]undec-7-ene / acetonitrile / 20 °C View Scheme

formic acid (64-18-6) + 2-Fluoroaniline (348-54-9) → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
Stage #1: formic acid With acetic anhydride at 0 - 50℃; Inert atmosphere; Stage #2: 2-Fluoroaniline In tetrahydrofuran at 20℃; Inert atmosphere; Stage #3: With hydrogenchloride; borane-THF

C13H13FN2O2S → 2-fluoro-N-methylaniline (1978-38-7)

Conditions	Yield
With ammonium hydroxide In water for 5h; Reflux; Large scale;	646 g

2-fluoro-N-methylaniline (1978-38-7) + (R)-2-[4-(4-cyano-2-fluorophenoxy)phenoxy]propanoyl chloride → C23H18F2N2O3

Conditions	Yield
With sodium hydroxide In toluene at 20 - 25℃; for 3h; Reagent/catalyst;	96.47%

(R)-(+)-2-[4-(5-chloro-3-fluoropyridin-2-yloxy)phenoxy]propanoyl chloride (101053-90-1) + 2-fluoro-N-methylaniline (1978-38-7) → (R)-2-(4-((5-chloro-3-fluoropyridin-2-yl)oxy)phenoxy)-N-(2-fluorophenyl)-N-methylpropionamide

Conditions	Yield
With sodium hydroxide In toluene at 20 - 25℃; for 3.5h;	96.46%

(2R)-2-{4-[(6-chloro-1,3-benzoxazol-2-yl)oxy]phenoxy}propanoic acid + 2-fluoro-N-methylaniline (1978-38-7) → metamifop

Conditions	Yield
Stage #1: (2R)-2-{4-[(6-chloro-1,3-benzoxazol-2-yl)oxy]phenoxy}propanoic acid With trifluorormethanesulfonic acid; 1,1'-carbonyldiimidazole In dichloromethane at 20℃; for 1.5h; Stage #2: 2-fluoro-N-methylaniline In dichloromethane at 20℃; for 3h; Solvent;	95.8%

2-fluoro-N-methylaniline (1978-38-7) + fenoxaprop-p-ethyl (66441-23-4, 71283-80-2) → (2R)-2-[4-[(6-chloro-1,3-benzoxazol-2-yl)oxy]phenoxy]-N-(2-fluorophenyl)-N-methylpropanamide (256412-89-2)

Conditions	Yield
With triethylamine In ethanol at 80℃; Solvent; Temperature; Reagent/catalyst;	95%

2-fluoro-N-methylaniline (1978-38-7) + 3-methyl-5H-1,4,2-dioxazol-5-one → N'-(2-fluorophenyl)-N'-methylacetohydrazide (1604806-78-1)

Conditions	Yield
With bis[dichloro(pentamethylcyclopentadienyl)iridium(III)] In chloroform at 25℃; for 12h; Inert atmosphere; Sealed tube;	95%

2-(2',2'-difluoroethoxy)-6-trifluoromethylbenzene-1-sulfonyl chloride (865352-01-8) + 2-fluoro-N-methylaniline (1978-38-7) → 2-(2,2-difluoroethoxy)-N-(2-fluorophenyl)-N-methyl-6-(trifluoromethyl)benzenesulfonamide

Conditions	Yield
With 3,5-Lutidine In dimethyl sulfoxide; toluene at 60 - 65℃; for 4.5h;	94.36%

5-bromothiophene-2-carbonyl chloride (31555-60-9) + 2-fluoro-N-methylaniline (1978-38-7) → 5-bromo-N-(2-fluorophenyl)-N-methylthiophene-2-carboxamide (1396244-28-2)

Conditions	Yield
With triethylamine at 0℃; for 3h;	94%

2-fluoro-N-methylaniline (1978-38-7) + phenazine-1-carboxylic acid chloride → N-(2-fluorophenyl)-N-methylphenazine-1-carboxamide

Conditions	Yield
In dichloromethane at 0 - 5℃; for 1h;	93%
With triethylamine In dichloromethane for 2h; Reflux;	93%

2-fluoro-N-methylaniline (1978-38-7) + acetyl chloride (75-36-5) → N-(2-fluorophenyl)-N-methylacetamide (120371-27-9)

Conditions	Yield
With pyridine In dichloromethane at 20℃; for 17h; Inert atmosphere;	91%

2-Bromo-6-[(S)-1-((R)-1-phenyl-ethyl)-pyrrolidin-2-yl]-pyridine (867327-09-1) + 2-fluoro-N-methylaniline (1978-38-7) → C24H26FN3

Conditions	Yield
tris-(dibenzylideneacetone)dipalladium(0); CyJohnPhos In toluene at 20 - 80℃; for 2h;	90.3%

(2R)-2-{4-[(6-chloro-1,3-benzoxazol-2-yl)oxy]phenoxy}propanoic acid + 2-fluoro-N-methylaniline (1978-38-7) → (2R)-2-[4-[(6-chloro-1,3-benzoxazol-2-yl)oxy]phenoxy]-N-(2-fluorophenyl)-N-methylpropanamide (256412-89-2)

Conditions	Yield
With oxalyl dichloride; triethylamine at 10 - 40℃; for 10h;	90%

2-fluoro-N-methylaniline (1978-38-7) → N-methylaniline (100-61-8)

Conditions	Yield
With sodium tetrafluoroborate; tetrabutylammonium tetrafluoroborate In 1-methyl-pyrrolidin-2-one at 60℃; for 3h; Electrochemical reaction; Green chemistry;	87%

2-fluoro-N-methylaniline (1978-38-7) + 2-Bromopropionic acid (598-72-1) → N-(2-Fluorophenyl)-N-methyl-2-bromo-propionamide (256412-87-0)

Conditions	Yield
With dicyclohexyl-carbodiimide In chloroform at 20℃; for 1h;	87%

2-fluoro-N-methylaniline (1978-38-7) + 2-Bromoacetyl bromide (598-21-0) → 2-bromo-N-(2-fluorophenyl)-N-methylacetamide (1339800-80-4)

Conditions	Yield
In dichloromethane at -10 - 20℃; for 17h; Inert atmosphere;	86%

2-fluoro-N-methylaniline (1978-38-7) + Methacryloyl chloride (920-46-7) → N-(2-fluorophenyl)-N-methylmethacrylamide (1449116-83-9)

Conditions	Yield
With potassium carbonate In water; acetone at 0℃; Inert atmosphere; Sealed tube; Schlenk technique;	85%
With triethylamine In dichloromethane at 0 - 20℃; for 6h; Inert atmosphere;	73%
With triethylamine In dichloromethane at 0 - 20℃; for 1h;
With triethylamine In dichloromethane at 0 - 20℃; for 1h;

2-fluoro-N-methylaniline (1978-38-7) + C21H20ClNO6 → (2R)-2-[4-[(6-chloro-1,3-benzoxazol-2-yl)oxy]phenoxy]-N-(2-fluorophenyl)-N-methylpropanamide (256412-89-2)

Conditions	Yield
at 5 - 25℃; for 13h; Large scale;	85%

2-fluoro-N-methylaniline (1978-38-7) + 2-phenylimidazo[1,2-a]pyridine (4105-21-9) → 2-fluoro-N-methyl-4-((2-phenylimidazo[1,2-a]pyridin-3-yl)thio)aniline

Conditions	Yield
With sulfur; dimethyl sulfoxide at 110℃; for 12h; Sealed tube;	83%

2-fluoro-N-methylaniline (1978-38-7) + isopropenylbenzene (98-83-9) → C16H18FN

Conditions	Yield
With C31H49N2ScSi2; N,N'-dimethylaniliniumtetrakis(pentafluorophenyl)borate In toluene at 20 - 120℃; for 36h;	82%
With C31H51N2ScSi2; N,N'-dimethylaniliniumtetrakis(pentafluorophenyl)borate In toluene at 120℃; for 36h; Inert atmosphere; chemoselective reaction;	82%
With 1,1,1,3',3',3'-hexafluoro-propanol; sodium acetate at 80℃; for 12h; chemoselective reaction;	81%

2-fluoro-N-methylaniline (1978-38-7) + ammonium thiocyanate (1147550-11-5) → C8H7FN2S

Conditions	Yield
With oxygen In tetrahydrofuran at 20℃; for 4h; Irradiation; chemoselective reaction;	82%

rac-methoxyphenylacetic acid (7021-09-2) + 2-fluoro-N-methylaniline (1978-38-7) → N-(2-fluorophenyl)-2-methoxy-N-methyl-2-phenylacetamide (1333643-96-1)

Conditions	Yield
With dmap; dicyclohexyl-carbodiimide In dichloromethane at 0 - 20℃; for 17h; Inert atmosphere; optical yield given as %de;	81%

2-nitrophenyl bromide (577-19-5) + 2-fluoro-N-methylaniline (1978-38-7) → 2-fluoro-N-methyl-N-(2-nitrophenyl)aniline (908242-57-9)

Conditions	Yield
With caesium carbonate; 2,2'-bis-(diphenylphosphino)-1,1'-binaphthyl; tris(dibenzylideneacetone)dipalladium (0) In toluene for 16h; Heating;	79%

1,6-dibromocyclohex-1-ene (17202-32-3) + 2-fluoro-N-methylaniline (1978-38-7) → N-(2-bromo-2-cyclohexenyl)-2-fluoro-N-methylaniline (475040-19-8)

Conditions	Yield
Stage #1: 2-fluoro-N-methylaniline With n-butyllithium In tetrahydrofuran; hexane at -50 - 20℃; for 1h; Stage #2: 1,6-dibromocyclohex-1-ene In tetrahydrofuran; hexane for 5.25h; Further stages.;	78%

Upstream product

• 348-54-9 2-Fluoroaniline 
• 74-88-4 methyl iodide 
• 824-48-6 N-(2-fluorophenyl)formamide 
• 900537-29-3 N-methyl-N-nosyl-o-fluoroaniline 
• 68-11-1 mercaptoacetic acid 
• 1766-57-0 N-(2-fluorophenyl)-4-nitrobenzenesulfonamide 
• 64-18-6 formic acid 
• 67-56-1 methanol 
• 50-00-0 formaldehyd 
• 1272654-63-3 N-methyl-N-(2-fluorophenyl)formamide 
• 616-38-6 carbonic acid dimethyl ester 
• 74-89-5 methylamine 

Downstream Products

• 55239-43-5 C₈H₇ClFNO 
• 475040-19-8 N-(2-bromo-2-cyclohexenyl)-2-fluoro-N-methylaniline 
• 117531-36-9 N-allyl-2-fluoroaniline 
• 475039-96-4 N-(2-bromobenzyl)-2-fluoro-N-methylaniline 
• 908242-57-9 N-(2-fluorophenyl)-N-methyl-2-nitroaniline 
• 928307-87-3 N-(2-bromo-4,5-methylenedioxybenzyl)-2-fluoro-N-methylaniline 
• 908242-59-1 N¹-(2-fluorophenyl)-N¹-methylbenzene-1,2-diamine 
• 908242-61-5 N-(2-fluorophenyl)-N-(2-iodophenyl)-methylamine 
• 1484-12-4 N-methylcarbazole 
• 502434-54-0 (2S)-3-(N-(2-fluorophenyl)-N-methylamino)-1, 2-propanediol 
• 67805-58-7 8-fluoro-1-methyl-1,2,3,4-tetrahydro-quinolin-2-one 
• 935440-47-4 3-fluoro-4-methylamino-benzenethiol 
• 1272654-63-3 N-methyl-N-(2-fluorophenyl)formamide 
• 1404461-96-6 C₁₈H₂₀FNO 

Relevant academic research and scientific papers

Synthesis method of N-methyl o-fluoroaniline

The invention relates to the field of preparation of pesticide and medical intermediates, and in particular, relates to a preparation method of N-methyl o-fluoroaniline, wherein the preparation method comprises the following steps: by taking o-fluoroaniline as a raw material and dimethyl carbonate as a reaction raw material and a reaction solvent, carrying out heat preservation reaction under the action of a basic catalyst; and after the reaction is finished, filtering to remove the catalyst, carrying out rectification separation on filtrate, and separating the solvent dimethyl carbonate from the product. Compared with the prior art, the novel synthesis method of N-methyl o-fluoroaniline provided by the invention has the following effective effects: only one-step reaction is needed, the selectivity is extremely high, the product quality is good, the selected methylation reagent dimethyl carbonate is low in toxicity, green and safe, the output of three wastes is low, and the novel synthesis method of N-methyl o-fluoroaniline is a green chemical process with extremely competitive power.

Preparation method for coproducing N-methyl-2-fluoroaniline and crystallized sulfanilamide

The invention discloses a preparation method for co-production of N-methyl-2-fluoroaniline and crystallized sulfanilamide. The preparation method comprises the following steps: S1, taking o-fluoroaniline, p-acetamidobenzenesulfonyl chloride and an acid-binding agent for condensation reaction to obtain a substance A; S2, performing methylation reaction on the substance A, a methylation reagent andan alkaline substance, and then performing amino deprotection to obtain a substance B; finally, subjecting the substance B and an aminating agent to be subjected to an ammonolysis reaction to obtain N-methyl-2-fluoroaniline and crystallized sulfanilamide. According to the preparation method, o-fluoroaniline and p-acetamidobenzenesulfonyl chloride are taken as raw materials, two substances, namelyN-methyl-2-fluoroaniline and crystallized sulfanilamide, are synchronously prepared, and the yield is relatively high.

Synthesis method of N-methyl o-fluoroaniline

The invention discloses a synthesis method of N-methyl o-fluoroaniline, which comprises the following steps: an amidation reaction: by using o-fluoroaniline as a raw material, mixing o-fluoroaniline with toluene and formic acid, heating to react, and dehydrating while reacting to obtain N-(2-fluorophenyl) formamide; a methylation reaction: taking N-(2-fluorophenyl) formamide as a raw material, adding dimethyl carbonate and a catalyst, putting into an autoclave, and heating to carry out the methylation reaction so as to obtain N-methyl-N-formyl-2-fluoroaniline; and a hydrolysis reaction: takingN-methyl-N-formyl-2-fluoroaniline as a raw material, mixing the N-methyl-N-formyl-2-fluoroaniline with water and sulfuric acid, carrying out hydrolysis, and carrying out post-treatment to obtain theN-methyl o-fluoroaniline. The method has the advantages of easily available raw materials, low raw material cost, mild reaction conditions, greenness, safety, high total yield (up to 90%), and great industrial application prospect.

Highly selective hydrogenation of amides catalysed by a molybdenum pincer complex: Scope and mechanism

A series of molybdenum pincer complexes has been shown for the first time to be active in the catalytic hydrogenation of amides. Among the tested catalysts, Mo-1a proved to be particularly well suited for the selective C-N hydrogenolysis of N-methylated formanilides. Notably, high chemoselectivity was observed in the presence of certain reducible groups including even other amides. The general catalytic performance as well as selectivity issues could be rationalized taking an anionic Mo(0) as the active species. The interplay between the amide CO reduction and the catalyst poisoning by primary amides accounts for the selective hydrogenation of N-methylated formanilides. The catalyst resting state was found to be a Mo-alkoxo complex formed by reaction with the alcohol product. This species plays two opposed roles-it facilitates the protolytic cleavage of the C-N bond but it encumbers the activation of hydrogen.

Manufacturing method for halogen substituted N-methylaniline

The present invention relates to a method for manufacturing halogen-substituted N-methylaniline from halogen-substituted aniline. When halogen-substituted N-methylaniline is manufactured by using the method of the present invention, it is possible to manufacture halogen-substituted N-methylaniline without using existing methoxide sodium which has low chemical stability and is expensive, by using a low-cost base having excellent chemical stability such as potassium hydroxide or sodium hydroxide. Therefore, it is possible to reduce costs in a manufacturing process and to produce N-methylaniline with a high yield and high purity, thereby being useful for mass production as a raw material for herbicide metamifop synthesis.COPYRIGHT KIPO 2019

Synthesis method of N-methyl-2-fluoroaniline

The invention belongs to the technical field of organic synthesis and particularly relates to a synthesis method of N-methyl-2-fluoroaniline. The synthesis method comprises the following steps: step one, mixing 2-fluoroaniline with concentrated hydrochloric acid, adding a sodium nitrite solution and carrying out thermal reaction to obtain 2-fluoroaniline diazonium salt; step two, adding the 2-fluoroaniline diazonium salt into a methylamine aqueous solution, and carrying out thermal reaction and post treatment to obtain the N-methyl-2-fluoroaniline. According to the method, the N-methyl-2-fluoroaniline with high yield and high selectivity can be obtained by taking the 2-fluoroaniline as a raw material, carrying out diazotization reaction on the 2-fluoroaniline and then carrying out high temperature reaction on the methylamine aqueous solution and a reactant; reaction raw materials are cheap and easily obtained; the process is reasonable, advanced and feasible; the obtained N-methyl-2-fluoroaniline has the advantages of high purity, good quality and capability of being industrially produced on a large scale.

The design, synthesis and evaluation of selenium-containing 4-anilinoquinazoline hybrids as anticancer agents and a study of their mechanism

Inhibition of tubulin polymerization is one of the significant strategies in the treatment of cancer. Inspired by the excellent antitumor activity of EP128495 and the beneficial biological activities of selenium compounds, a series of new selenium-containing 4-anilinoquinazoline hybrids were synthesized and evaluated as tubulin polymerization inhibitors. An anti-proliferative activity assay showed that most of the compounds inhibited human sensitive cancer cells at low nanomolar concentrations. A mechanism study revealed that the optimal compound 5a disrupted microtubule dynamics, decreased the mitochondrial membrane potential and arrested HeLa cells in the G2/M phase, finally resulting in cellular apoptosis.

A N - methyl [...] aniline synthesis method (by machine translation)

The invention discloses a N - methyl [...] aniline synthesis method, comprises the following steps: comprises the following steps: (1) in order to [...] aniline as raw materials, adding toluene, paraformaldehyde and catalyst A, thermal insulation reaction after dehydration, post-processing to obtain N - methylene [...] aniline; (2) the N - methylene [...] aniline, catalyst B into a high-pressure, nitrogen after the replacement, the hydrogen gas and maintain a certain pressure, the temperature of the hydrogenation reaction, after treatment shall be N - methyl [...] aniline. The method can have easy availability of raw materials, mild reaction conditions, material cost is relatively low, to avoid impurity inclusion agent such enormous advantages, has great prospects for industrial application. (by machine translation)

N-Methylation of Amines with Methanol Catalyzed by a Cp?Ir Complex Bearing a Functional 2,2′-Bibenzimidazole Ligand

A new type of Cp?Ir complex bearing a functional 2,2′-bibenzimidazole ligand was designed, synthesized, and found to be a highly effective and general catalyst for the N-methylation of a variety of amines with methanol in the presence of a weak base (0.3 equiv of Cs2CO3).

PHENYLACETIC ACID COMPOUND

A compound represented by formula (I), wherein R1 represents a hydrogen atom, etc., R2 and R3 each independently represents a hydrogen atom, optionally oxidized C1-4 alkyl group or optionally protected hydroxyl group, or R2 and R3 taken together represent optionally oxidized C2-5 alkylene group, R4 represents an optionally oxidized C1-6 alkyl group, etc., R5 represents an optionally oxidized C1-6 alkyl group, etc., R6 represents an optionally oxidized C1-6 alkyl group, etc., m represents 0 or an integer from 1 to 3, n represents 0 or an integer from 1 to 4, and i represents 0 or an integer from 1 to 7.