695-98-7

Basic information

• Product Name: 2,3,5-Collidine
• Synonyms: 235CO;2,3,5-COLLIDINE;2,3,5-TRIMETHYLPYRIDINE;Pyridine, 2,3,5-trimethyl-;2,3,5-Collidine, 99+%;2,3,5-COLLIDINE 2,3,5-TRIMETHYLPYRIDINE;2,3,5-Trimethyl pyridine ,99%;2,3,5-TrimethylpyridineD449525
• CAS NO: 695-98-7
• Molecular Formula: C₈H₁₁N
• Molecular Weight: 121.18
• EINECS: 211-786-1
• Product Categories: Pyridines derivates;Aromatics;Heterocycles;Intermediates & Fine Chemicals;Pharmaceuticals
• Mol File: 695-98-7.mol
• Article Data: 12

Chemical Properties

• Melting Point: -56.98°C (estimate)
• Boiling Point: 184 °C(lit.)
• Flash Point: 165 °F
• Appearance: Clear colorless to very slightly yellow/Liquid
• Density: 0.931 g/mL at 25 °C(lit.)
• Refractive Index: n20/D 1.508(lit.)
• Storage Temp.: Refrigerator
• Solubility: Chloroform (Slightly), Methanol (Slightly)
• PKA: 6.53±0.20(Predicted)
• Water Solubility: SLIGHTLY SOLUBLE
• BRN: 108832
• CAS DataBase Reference: 2,3,5-Collidine(CAS DataBase Reference)
• NIST Chemistry Reference: 2,3,5-Collidine(695-98-7)
• EPA Substance Registry System: 2,3,5-Collidine(695-98-7)

Safety Data

• Hazard Codes: Xi,T,Xn
• Statements: 36/37/38-20/21/22
• Safety Statements: 26-36-36/37
• RIDADR: NA 1993 / PGIII
• WGK Germany: 3
• HazardClass: 6.1
• Hazardous Substances Data: 695-98-7(Hazardous Substances Data)

Usage

Chemical Properties

clear colourless to very slightly yellow liquid

Uses

Different sources of media describe the Uses of 695-98-7 differently. You can refer to the following data:
1. Omeprazole intermediate.
2. 2,3,5-Collidine is omeprazole intermediate which is the drug involved in proton pump inhibitors to block the production of stomach acid. It is used in the manufacture vitamin D3.

InChI:InChI=1/C8H11N/c1-6-4-7(2)8(3)9-5-6/h4-5H,1-3H3

Synthetic route

C8H12ClN → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With potassium tert-butylate In tetrahydrofuran for 1h; Reflux;	91%

3,5-Lutidine (591-22-0) + propan-1-ol (71-23-8) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With Raney nickel at 180℃; for 0.5h; Concentration; Flow reactor; Green chemistry; regioselective reaction;	90%

2,4-dichloro-3,5,6-trimethylpyridine (109371-17-7) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With ammonium hydroxide; hydrogen; palladium on activated charcoal In ethanol under 2250.2 Torr; for 3h; further reagent zinc powder, H2SO4;	83%

2,4-dichloro-3,5,6-trimethylpyridine (109371-17-7) → 2,3,5-trimethyl-pyridine (695-98-7) + 4-chloro-2,3,5-trimethylpyridine (109371-18-8) + 2-chloro-3,5,6-trimethylpyridine (121767-77-9)

Conditions	Yield
With sulfuric acid; hydrogen; palladium on activated charcoal In ethanol at 20℃; under 1500.1 Torr;	A n/a B 78% C n/a

dimethylacetylene (503-17-3) + 2-methylallylamin (2878-14-0) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With potassium hexafluorophosphate; [ruthenium(II)(η6-1-methyl-4-isopropyl-benzene)(chloride)(μ-chloride)]2; copper diacetate In tert-Amyl alcohol at 100℃; for 24h; Inert atmosphere; Schlenk technique; regioselective reaction;	45%

3,5-Lutidine (591-22-0) + methyllithium (917-54-4) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With diethyl ether; toluene

3-chloromethyl-2,5-dimethyl-pyridine (856851-26-8) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With methanol; palladium on activated charcoal Hydrogenation;

N-methyl-3,5-dimethylpyridinium iodide (22739-24-8) → 2,3,5-trimethyl-pyridine (695-98-7) + 2,3,5,6-tetramethylpyridine (3748-84-3)

Conditions	Yield
at 300 - 320℃; im Rohr;
at 300 - 320℃; im Rohr;

acetaldehyde (75-07-0) + propionaldehyde (123-38-6) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With aluminum oxide; ammonia at 330 - 340℃;

3-methyl-butan-2-one oxime (600-20-4) + propionaldehyde (123-38-6) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With piperidine hydrochloride In toluene at 200℃; for 2h; autoclave;	6 % Chromat.

ammonia (7664-41-7) + acetaldehyde (75-07-0) + propionaldehyde (123-38-6) → 3,4-Lutidin (583-58-4) + 2,3,5-trimethyl-pyridine (695-98-7)

ammonia (7664-41-7) + acetaldehyde (75-07-0) + propionaldehyde (123-38-6) + aluminium oxide → 3,4-Lutidin (583-58-4) + 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
at 330 - 340℃;

formaldehyde diethyl acetal (462-95-3) + ammonia (7664-41-7) + propionaldehyde (123-38-6) + aluminium oxide → pyridine (110-86-1) + 3,5-Lutidine (591-22-0) + 3,4-Lutidin (583-58-4) + 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
at 330 - 375℃; aus technischem,acetaldehydhaltigem Propionaldehyd; Produkt 5: β-Picolin;

3-methyl-butan-2-one (563-80-4) + MeMgX → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: 74 percent / NaOH, NH2OH*HCl / H2O; ethanol / 1 h / 6 °C 2: 6 percent Chromat. / piperidine*HCl / toluene / 2 h / 200 °C / autoclave View Scheme

4-hydroxy-3,5,6-trimethyl-2(1H)-pyridone (109371-16-6) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: 95 percent / phosphoryl chloride / 4 h / 150 °C 2: 83 percent / hydrogen, conc. NH3 / 10percent Pd/C / ethanol / 3 h / 2250.2 Torr / further reagent zinc powder, H2SO4 View Scheme
Multi-step reaction with 2 steps 1: 95 percent / phosphoryl chloride / 4 h / 150 °C 2: hydrogen, conc. H2SO4 / 10percent Pd/C / ethanol / 20 °C / 1500.1 Torr View Scheme

(2,5-Dimethyl-[3]pyridyl)-methanol (194342-46-6) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: thionyl chloride 2: palladium/charcoal; methanol / Hydrogenation View Scheme

3-(ethoxycarbonyl)-2,5-dimethylpyridine (31931-53-0) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
Multi-step reaction with 3 steps 1: lithium alanate; diethyl ether / und anschliessendes Erwaermen. 2: thionyl chloride 3: palladium/charcoal; methanol / Hydrogenation View Scheme

6-hydroxy-2,5-dimethyl-nicotinic acid ethyl ester (57180-01-5) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
Multi-step reaction with 5 steps 1: PCl5 / 160 - 170 °C 2: palladium/charcoal; methanol / Hydrogenation 3: lithium alanate; diethyl ether / und anschliessendes Erwaermen. 4: thionyl chloride 5: palladium/charcoal; methanol / Hydrogenation View Scheme

6-chloro-2,5-dimethyl-nicotinic acid ethyl ester (846541-99-9) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
Multi-step reaction with 4 steps 1: palladium/charcoal; methanol / Hydrogenation 2: lithium alanate; diethyl ether / und anschliessendes Erwaermen. 3: thionyl chloride 4: palladium/charcoal; methanol / Hydrogenation View Scheme

2-methylpropenal (78-85-3) + butanone (78-93-3) → 3,5-Lutidine (591-22-0) + 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With ammonia; zeolite Gas phase;

sulfuric acid (7664-93-9) + 2,4-dichloro-3,5,6-trimethylpyridine (109371-17-7) + zinc (7440-66-6) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With sodium hydroxide

conc. aqueous ammonia + 2,4-dichloro-3,5,6-trimethylpyridine (109371-17-7) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
palladium-carbon In ethanol

3,5-Lutidine (591-22-0) + 1-Decanol (112-30-1) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With Ra-Ni for 68h; Reflux; regioselective reaction;

(E)-but-2-enoic acid (107-93-7) + C10H17NO2 → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With dipotassium peroxodisulfate; (pentamethylcyclopentadienyl)*Rh(OAc)2; silver(I) 4-methylbenzenesulfonate at 80℃; Reagent/catalyst;	80 %Spectr.

(E)-but-2-enoic acid (107-93-7) + C10H17NO2 → 2,3,5-trimethyl-pyridine (695-98-7) + C9H11NO2 (1087730-24-2)

Conditions	Yield
With dipotassium peroxodisulfate; (pentamethylcyclopentadienyl)*Rh(OAc)2 at 80℃;	A 15 %Spectr. B 15 %Spectr.

3-Methyl-3-buten-2-one (814-78-8) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
Multi-step reaction with 3 steps 1: hydroxylamine hydrochloride; sodium carbonate / methanol / 1 h / 65 °C / Inert atmosphere 2: triethylamine / dichloromethane / 0 - 20 °C / Inert atmosphere 3: dipotassium peroxodisulfate; (pentamethylcyclopentadienyl)*Rh(OAc)2 / 80 °C View Scheme

3-methyl-3-buten-2-one oxime (20963-51-3, 28051-69-6, 39847-77-3) → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
Multi-step reaction with 2 steps 1: triethylamine / dichloromethane / 0 - 20 °C / Inert atmosphere 2: dipotassium peroxodisulfate; (pentamethylcyclopentadienyl)*Rh(OAc)2 / 80 °C View Scheme

C19H27ClNO2Rh → 2,3,5-trimethyl-pyridine (695-98-7)

Conditions	Yield
With silver(I) 4-methylbenzenesulfonate at 58℃; Inert atmosphere;

2,3,5-trimethyl-pyridine (695-98-7) + 1-Iodohexane (638-45-9) → 1-hexyl-2,3,5-trimethylpyridinium iodide (1345623-07-5)

Conditions	Yield
In toluene at 110℃; for 96h;	99%

2,3,5-trimethyl-pyridine (695-98-7) + formamide (77287-34-4, 77287-35-5, 60100-09-6) → 3,5,6-trimethylpicolinamide

Conditions	Yield
With dipotassium peroxodisulfate; oxygen; sodium formate; silver nitrate In water at 80℃; for 4h; Schlenk technique; regioselective reaction;	96%

acetamide (60-35-5) + 2,3,5-trimethyl-pyridine (695-98-7) → 3,5,6-trimethylpicolinamide

Conditions	Yield
With dipotassium peroxodisulfate; oxygen; sodium acetate; iron(II) chloride In water at 80℃; for 4h; Green chemistry;	96%

2,3,5-trimethyl-pyridine (695-98-7) + dichloromethane (75-09-2) + dihydrogen peroxide (7722-84-1) → 2,3,5-trimethylpyridine 1-oxide (74409-42-0)

Conditions	Yield
With sodium hydroxide; acetic acid	94%

2,3,5-trimethyl-pyridine (695-98-7) + trichloroisocyanuric acid (87-90-1) + benzamide (55-21-0) → 2-chloromethyl-3,5-dimethyl-4-nitro-pyridine N-oxide (142885-89-0)

Conditions	Yield
With sodium hydroxide In water	93%

2,3,5-trimethyl-pyridine (695-98-7) → 2,3,5-trimethylpyridine 1-oxide (74409-42-0)

Conditions	Yield
With dihydrogen peroxide; methyltrioxorhenium(VII) In dichloromethane; water at 20℃; for 3h;	91%
With 3-chloro-benzenecarboperoxoic acid In dichloromethane at 1 - 20℃; for 13.5h; Product distribution / selectivity;	88.3%
With dihydrogen peroxide In acetic acid at 90 - 95℃; for 9h;	85%

2,3,5-trimethyl-pyridine (695-98-7) + 1-cyanoethyl trifluoromethanesulfonate (1403873-31-3) → 1-(1-cyanoethyl)-2,3,5-trimethylpyridinium triflate

Conditions	Yield
In diethyl ether at 20℃; for 48h; Inert atmosphere;	91%

2,3,5-trimethyl-pyridine (695-98-7) + methyl iodide (74-88-4) → 2,3,5,6-tetramethylpyridine (3748-84-3) + 2-ethyl-3,5-dimethylpyridine (1123-96-2)

Conditions	Yield
Stage #1: 2,3,5-trimethyl-pyridine With n-butyllithium In diethyl ether; hexane for 1.16667h; Inert atmosphere; Stage #2: methyl iodide In diethyl ether; hexane at -78 - 20℃; Inert atmosphere;	A 8% B 85%

2,3,5-trimethyl-pyridine (695-98-7) + 1-bromo-butane (109-65-9) → 2-pentyl-3,5-dimethylpyridine (1345623-05-3)

Conditions	Yield
Stage #1: 2,3,5-trimethyl-pyridine With n-butyllithium In diethyl ether; hexane for 1.16667h; Inert atmosphere; Stage #2: 1-bromo-butane In diethyl ether; hexane at -78 - 20℃; Inert atmosphere;	84%

2,3,5-trimethyl-pyridine (695-98-7) + di-tert-butyl dicarbonate (24424-99-5) → tert-butyl (3,5-dimethylpyridin-2-yl)acetate (1104643-33-5)

Conditions	Yield
Stage #1: 2,3,5-trimethyl-pyridine With lithium diisopropyl amide In tetrahydrofuran; hexane at -78℃; for 0.5h; Stage #2: di-tert-butyl dicarbonate In tetrahydrofuran; hexane at -78 - 20℃; for 2h;	83%

2,3,5-trimethyl-pyridine (695-98-7) + diphenyl diselenide (1666-13-3) + α-bromoacetophenone (70-11-1) → 6,8-dimethyl-2-phenyl-1,3-bis(phenylselanyl)indolizine

Conditions	Yield
With potassium carbonate; potassium iodide In water; N,N-dimethyl-formamide at 50℃; for 8h; Electrolysis;	80%

2,3,5-trimethyl-pyridine (695-98-7) + 2-bromo-1-(2-bromo-4,5-dimethoxyphenyl)-ethanone (321681-28-1) → 1-[2-(2-bromo-4,5-dimethoxyphenyl)-2-oxoethyl]-2,3,5-trimethylpyridinium bromide (1268015-48-0)

Conditions	Yield
In acetone at 50℃; for 48h;	79%

2,3,5-trimethyl-pyridine (695-98-7) + 2,2'-dibromoacetophenone (49851-55-0) → 1-[2-(2-bromophenyl)-2-oxoethyl]-2,3,5-trimethylpyridinium bromide (1268015-29-7)

Conditions	Yield
In acetone at 50℃; for 48h;	77%

2,3,5-trimethyl-pyridine (695-98-7) + n-butyllithium (109-72-8, 29786-93-4) + methyl iodide (74-88-4) → 2,3,5,6-tetramethylpyridine (3748-84-3) + 2-ethyl-3,5-dimethylpyridine (1123-96-2) + 2-pentyl-3,5-dimethylpyridine (1345623-05-3)

Conditions	Yield
Stage #1: 2,3,5-trimethyl-pyridine; n-butyllithium In diethyl ether; hexane for 1.16667h; Inert atmosphere; Stage #2: methyl iodide In diethyl ether; hexane at -78 - 20℃; Inert atmosphere;	A 13% B 13% C 69%

2,3,5-trimethyl-pyridine (695-98-7) + n-butyllithium (109-72-8, 29786-93-4) + methyl iodide (74-88-4) → 2-ethyl-3,5-dimethylpyridine (1123-96-2) + 2-pentyl-3,5-dimethylpyridine (1345623-05-3)

Conditions	Yield
Stage #1: 2,3,5-trimethyl-pyridine; n-butyllithium In diethyl ether; hexane for 1.16667h; Inert atmosphere; Stage #2: methyl iodide In diethyl ether; hexane at -78 - 20℃; Inert atmosphere;	A 27% B 69%

2,3,5-trimethyl-pyridine (695-98-7) + imidazo[1,2-a]pyridine (274-76-0) → (3,5-dimethylpyridin-2-yl)(imidazo[1,2-a]pyridin-3-yl)methanone

Conditions	Yield
With oxygen; copper diacetate; trifluoroacetic acid In toluene at 130℃; Schlenk technique; Sealed tube; regioselective reaction;	63%

2,3,5-trimethyl-pyridine (695-98-7) + 2-Mercapto-5-methoxybenzimidazole (37052-78-1) + trifluoroacetic anhydride (407-25-0) → omeprazole (73590-58-6)

Conditions

Yield

Stage #1: 2,3,5-trimethyl-pyridine With phosphotungstic acid; dihydrogen peroxide In acetonitrile; benzene at 95℃; for 1.5h; Molecular sieve; Stage #2: trifluoroacetic anhydride In chloroform; acetonitrile; benzene for 4.5h; Reflux; Molecular sieve; Stage #3: 2-Mercapto-5-methoxybenzimidazole With sodium hydroxide In ethanol; chloroform; acetonitrile; benzene at 25 - 29℃; for 3h; Temperature; Molecular sieve;

55.6%

2,3,5-trimethyl-pyridine (695-98-7) + p-toluenesulfonyl chloride (98-59-9) → C15H18N2O2S (1361106-69-5)

Conditions	Yield
Stage #1: 2,3,5-trimethyl-pyridine With O-(2,4-dinitrophenyl)hydroxylamine In tetrahydrofuran; water at 40℃; for 12h; Stage #2: p-toluenesulfonyl chloride With sodium hydroxide In tetrahydrofuran; water at 20℃; for 4h;	26%

2,3,5-trimethyl-pyridine (695-98-7) → 5,6-dimethylpyridine-3-carboxylic acid (757903-81-4) + 2,5-dimethyl-nicotinic acid (129477-22-1)

Conditions	Yield
With permanganate(VII) ion at 20℃;

2,3,5-trimethyl-pyridine (695-98-7) → (3,5-dimethyl-[2]pyridyl)-acetic acid ethyl ester

Conditions	Yield
With diethyl ether; phenyllithium Behandeln des Reaktionsgemisches mit Kohlensaeure-diaethylester;

2,3,5-trimethyl-pyridine (695-98-7) → pyridine-2,3,5-tricarboxylic acid (116668-76-9)

Conditions	Yield
With potassium permanganate
With potassium permanganate
Stage #1: 2,3,5-trimethyl-pyridine With potassium permanganate In water at 20 - 70℃; for 14h; Stage #2: With hydrogenchloride In water pH=3;

Upstream product

• 846541-99-9 6-chloro-2,5-dimethyl-nicotinic acid ethyl ester 
• 591-22-0 3,5-Lutidine 
• 112-30-1 1-Decanol 
• 107-93-7 (E)-but-2-enoic acid 
• 814-78-8 3-Methyl-3-buten-2-one 
• 20963-51-3 3-methylbut-3-en-2-one oxime 
• 71-23-8 propan-1-ol 
• 503-17-3 dimethylacetylene 
• 2878-14-0 2-methylallylamin 
• 109371-17-7 2,4-dichloro-3,5,6-trimethylpyridine 
• 7664-93-9 sulfuric acid 
• 7440-66-6 zinc 
• 78-85-3 2-methylpropenal 
• 78-93-3 butanone 

Downstream Products

• 86604-79-7 2,3,5-trimethyl-4-nitropyridine N-oxide 
• 73590-58-6 omeprazole 
• 1334333-29-7 methyl 4-(3,5-dimethylpyridin-2-yl)-2-methylene-3-phenylbutanoate 
• 142885-96-9 2-chloromethyl-4-chloro-3,5-dimethylpyridine 
• 1361106-69-5 C₁₅H₁₈N₂O₂S 
• 70580-28-8 C₈H₁₁NO*ClH 

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