625-84-3

Basic information

• Product Name: 2,5-Dimethyl-1H-pyrrole
• Synonyms: 2,5-1H-dimethylpyrrole;2,5-dimethyl-1h-pyrrol;2,5-dimethyl-pyrrol;Pyrrole, 2,5-dimethyl-;pyrrole,2,5-dimethyl-;Dimethylpyrrole;2,5-DIMETHYLPYRRAZOLE;1H-Pyrrole, 2,5-dimethyl-
• CAS NO: 625-84-3
• Molecular Formula: C₆H₉N
• Molecular Weight: 95.14
• EINECS: 210-913-8
• Product Categories: Building Blocks;Heterocyclic Building Blocks;Pyrroles
• Mol File: 625-84-3.mol
• Article Data: 26

Chemical Properties

• Melting Point: 6.5°C
• Boiling Point: 165 °C740 mm Hg(lit.)
• Flash Point: 130 °F
• Appearance: Yellow to orange-yellow/Crystalline Powder and/or Chunks
• Density: 0.935 g/mL at 25 °C(lit.)
• Vapor Pressure: 2.5mmHg at 25°C
• Refractive Index: n20/D 1.505(lit.)
• Storage Temp.: Refrigerator
• PKA: 18.46±0.50(Predicted)
• Water Solubility: Insoluble in water
• CAS DataBase Reference: 2,5-Dimethyl-1H-pyrrole(CAS DataBase Reference)
• NIST Chemistry Reference: 2,5-Dimethyl-1H-pyrrole(625-84-3)
• EPA Substance Registry System: 2,5-Dimethyl-1H-pyrrole(625-84-3)

Safety Data

• Hazard Codes: T,F
• Statements: 10-23/24/25-36/37/38
• Safety Statements: 16-26-36/37/39-45
• RIDADR: UN 1992 3/PG 3
• WGK Germany: 3
• RTECS: UX9465930
• HazardClass: 3.2
• PackingGroup: III
• Hazardous Substances Data: 625-84-3(Hazardous Substances Data)

Usage

Synthesis Reference(s)

Synthetic Communications, 18, p. 167, 1988 DOI: 10.1080/00397918808077341Synthesis, p. 1585, 2000 DOI: 10.1055/s-2000-7618

Safety Profile

When heated to decomposition emits toxic fumes of NOx

InChI:InChI=1/C6H9N/c1-5-3-4-6(2)7-5/h3-4,7H,1-2H3

Synthetic route

2,5-hexanedione (110-13-4) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
With ammonia In methanol at 0 - 110℃; under 2625.26 Torr; Paal-Knorr pyrrole synthesis;	100%
With aluminum oxide; 1,1,1,3,3,3-hexamethyl-disilazane at 100 - 110℃; for 0.333333h; Product distribution; other diones; var. temperatures and reaction times;	81%
With ammonium carbonate at 95 - 115℃; Product distribution / selectivity; Inert atmosphere;	78%

hexa-1,5-diyne (628-16-0) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
With AuC27H42N2(1+)*B(C6F5)4(1-)=(AuC27H42N2)(B(C6F5)4); ammonia In benzene-d6 at -60 - 135℃; Inert atmosphere;	96%
With ammonia; AuC27H42N2(1+)*B(C6F5)4(1-)=(AuC27H42N2)(B(C6F5)4) In benzyl methyl ether; benzene-d6 at -60 - 135℃; Product distribution / selectivity;	96%

Ni{η2-C(N-tBu)CH2CMe3}(C4H2Me2)(PMe3) → 2,5-Dimethylpyrrole (625-84-3) + Ni(CO3){C(NH(C(CH3)3)(CH2C(CH3)3))}(P(CH3)3)*H2O

Conditions	Yield
With carbon dioxide; water In acetone under N2, addn. of a few drops of H2O to a soln. of the complex, replaceing N2 with CO2 (3 atm), keeping the soln. undistrubed overnight, pptn.; filtered, washed (acetone), vac. dried, elem. anal.;	A n/a B 90%

2,5-hexanedione (110-13-4) → 2,5-Dimethylpyrrole (625-84-3) + 2,5-dimethyl-3,4-dihydro-2h-pyrrol-2-ol (110466-52-9)

Conditions	Yield
With ammonia	A 15% B 85%
With ammonium hydroxide at 5 - 10℃; for 10h;
With ammonia Yields of byproduct given;

2,5-hexanedione (110-13-4) + 1,1,1,3,3,3-hexamethyl-disilazane (999-97-3) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
With trifluorormethanesulfonic acid for 0.25h;	81%

2,5-dimethylfuran (625-86-5) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
With ammonia In n-heptane at 150℃; under 15001.5 Torr; for 3h; Inert atmosphere;	62%
With ammonia Leiten ueber Aluminiumoxid bei 450grad;
With ammonium hydroxide; NaY zeolite (LZY-54) In water at 350℃; under 52476.2 - 130050 Torr; for 4h; Product distribution / selectivity; Inert atmosphere;
With ammonium hydroxide; iron(II) sulfate; aluminium at 300℃;

Ni{η2-C(N-tBu)CH2CMe3}(C4H2Me2)(PMe3) + oxalic acid (144-62-7) → 2,5-Dimethylpyrrole (625-84-3) + Ni(C2O4){C(NH(C(CH3)3)(CH2C(CH3)3))}(P(CH3)3)*H2O

Conditions	Yield
With water In acetone under N2, addn. of solid H2C2O4*2H2O to a soln. of the complex, stirring, room temp., 4 h, pptn.; filtered, washed (acetone), vac. dried, elem. anal.;	A n/a B 60%

parabanic acid (120-89-8) + Ni{η2-C(N-tBu)CH2CMe3}(C4H2Me2)(PMe3) → 2,5-Dimethylpyrrole (625-84-3) + Ni(C3O3N2){C(NH(C(CH3)3)(CH2C(CH3)3))}(P(CH3)3)

Conditions	Yield
In methanol; acetone under N2, addn. (via canula) of a soln. of H2C3N2O3 in MeOH to a soln. of the complex in acetone, stirring overnight at room temp.; vac. evapn. to dryness, residue triturated with Et2O, pptn., filtered, dried;	A n/a B 60%

sodium cyanide (143-33-9) + N-(2,5-dimethylpyrrol-1-yl)pyridinium iodide (78133-60-5) → 2,5-Dimethylpyrrole (625-84-3) + pyridine-4-carbonitrile (100-48-1)

Conditions	Yield
In water at 100℃; for 0.5h;	A n/a B 33%

2,5-dimethyl-Δ3-pyrroline (59480-92-1) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
With 1-hydroxy-3H-benz[d][1,2]iodoxole-1,3-dione In dimethyl sulfoxide at 45℃; for 13h;	23%

2,5-dimethylpyrrolide (3378-71-0) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
With magnesium hydrosilicate; palladium at 300℃;

1-formyl-2,5-dimethyl-pyrrole (97142-87-5) + furan-2,3,5(4H)-trione pyridine (1:1) → 2,5-Dimethylpyrrole (625-84-3)

2,5-dimethyl-1H-pyrrole-3-carboxylic acid ethyl ester (2199-52-2) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
With soda lime at 100℃;

2,5-hexanedione (110-13-4) → 2,5-dimethylpyrrolide (3378-71-0) + 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
With methanol; ammonia; nickel at 150℃; under 110326 Torr; Hydrogenation;

2,5-dimethyl-1H-pyrrole-3,4-dicarboxylic acid (90222-74-5) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
beim Schmelzen;

4-isopropylidene-3-methylisoxazol-5(4H)-one (17975-59-6) → 2,4-dimethyl-1H-pyrrole (625-82-1) + 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
at 550 - 700℃; under 0.0005 Torr; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

(2,5-dimethyl-1H-pyrrol-1-yl)(phenyl)methanone (5044-32-6) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
In isopropyl alcohol at 80℃; for 72h; Yield given;

D-glucose (50-99-7) + glycine (56-40-6) → (2-furyl)methyl alcohol (98-00-0) + 2,5-Dimethylpyrrole (625-84-3) + 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (28564-83-2) + 2-Acetylpyrrole (1072-83-9) + acetic acid (64-19-7) + propionic acid (802294-64-0)

Conditions	Yield
In water at 95℃; for 2h; Product distribution; other reaction time, other temperature;

2,5-dimethyl-3,4-dihydro-2h-pyrrol-2-ol (110466-52-9) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
at 25℃;

2.5-dimethyl-pyrrole-carboxylic acid-(3) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
at 210 - 213℃;
With hydrogenchloride

2.5-dimethyl-pyrrole-dicarboxylic acid-(3.4) → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
durch Erhitzen ueber den Schmelzpunkt;
With hydrogenchloride

5-carboxymethyl-2-methyl-furan-3-carboxylic acid (534-60-1) + ammonium hydroxide → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
at 320℃; im geschlossenen Rohr;

2,5-hexanedione (110-13-4) + ammonium carbonate → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
at 100 - 115℃;

methyl iodide (74-88-4) + pyrrole magnesium bromide → 2,5-Dimethylpyrrole (625-84-3)

2,5-dimethyl-1H-pyrrole-3,4-dicarboxylic acid (90222-74-5) + strong acids → 2,5-Dimethylpyrrole (625-84-3)

2,5-dimethyl-2,3-dihydro-pyrrole-2-carboxylic acid + lime/chalk/ → 2,5-Dimethylpyrrole (625-84-3) + 2.5-dimethyl-pyrroline

Conditions	Yield
bei der Destillation;

diethyl ether (60-29-7) + 2,5-hexanedione (110-13-4) + magnesium amide iodide → 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
Zersetzen des Reaktionsprodukts mit waessr.Ammoniumchlorid-Loesung;

methanol (67-56-1) + ammonia (7664-41-7) + 2,5-hexanedione (110-13-4) + Raney nickel → 2,5-dimethylpyrrolide (3378-71-0) + 2,5-Dimethylpyrrole (625-84-3)

Conditions	Yield
under 110326 Torr;

prop-1-yne (74-99-7) + acetone oxime (127-06-0) → 2,4-dimethyl-1H-pyrrole (625-82-1) + 2,5-Dimethylpyrrole (625-84-3) + 2,4-Dimethyl-N-2-propenylpyrrole + 2,5-Dimethyl-N-2-propenylpyrrole

Conditions	Yield
With potassium hydroxide In dimethyl sulfoxide at 118 - 128℃; for 6h; Cycloaddition;

2,5-Dimethylpyrrole (625-84-3) + 2,4,5-tris(methylsulfanyl)-2H-1,3-dithiol-2-ylium tetrafluoroborate → 2-(2,5-dimethyl-3-pyrrolyl)-4,5-bis-methylthio-1,3-dithiolium-tetrafluoroborate

Conditions	Yield
In acetonitrile	100%
In acetonitrile for 4h; Ambient temperature;	99%

2,5-Dimethylpyrrole (625-84-3) + N-methylpyrrole aldehyde (1192-58-1) + tetrafluoroboric acid diethyl ether (67969-82-8) → BF4(1-)*C12H14N2*H(1+)

Conditions	Yield
In acetonitrile at 20℃; for 0.5h;	100%

2,5-Dimethylpyrrole (625-84-3) + p-toluidine (106-49-0) → 2,5-dimethyl-1-p-tolyl-1H-pyrrole (5044-26-8)

Conditions	Yield
In various solvent(s) at 110℃; pH=3;	99%

2,5-Dimethylpyrrole (625-84-3) + 2-methyl-4-methoxyaniline (102-50-1) → 1-(4-methoxy-2-methyl-phenyl)-2,5-dimethyl-1H-pyrrole

Conditions	Yield
In various solvent(s) at 110℃; pH=3;	99%

2,5-Dimethylpyrrole (625-84-3) + triethylaluminum (97-93-8) → 1-(diethylalumino)dimethylpyrrole

Conditions	Yield
In toluene at 20℃; for 5h; Glovebox; Inert atmosphere; Schlenk technique;	99%
In toluene at 20℃; for 5h; Inert atmosphere;	99%

2,5-Dimethylpyrrole (625-84-3) + 4-methoxy-aniline (104-94-9) → 1-(4-methoxyphenyl)-2,5-dimethyl-1H-pyrrole (5044-27-9)

Conditions	Yield
In various solvent(s) at 110℃; pH=3;	98%
With indium(III) tris[bis(trifluoromethanesulfonyl)amide] In 1,4-dioxane at 120℃; for 32h; Schlenk technique; Inert atmosphere;	83%

2,5-Dimethylpyrrole (625-84-3) + 1-bromopyrene (1714-29-0) → 2-(pyrene-1-yl)-2,5-dimethyl-2H-pyrrole

Conditions	Yield
Stage #1: 2,5-Dimethylpyrrole With n-butyllithium at 0℃; for 0.25h; Inert atmosphere; Stage #2: 1-bromopyrene With bis(dibenzylideneacetone)-palladium(0); ruphos at 100℃; for 12h; Inert atmosphere; regioselective reaction;	96%

2,5-Dimethylpyrrole (625-84-3) + 2-(1,5-dihydro-3-methyl-5-oxo-1-phenyl-4H-pyrazol-4-ylidene)propanedinitrile (117506-45-3) → 2-(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-2-(2,5-dimethyl-1H-pyrrol-3-yl)malononitrile (137123-48-9)

Conditions	Yield
In acetic acid for 2h; Ambient temperature;	95%

2,5-Dimethylpyrrole (625-84-3) + methyl 4-chlorocinnamate (7560-44-3, 20754-21-6, 20754-24-9) → methyl 4-(4-chlorophenyl)-4-(2,5-dimethyl-1H-pyrrol-3-yl)-2-oxobutanoate

Conditions	Yield
Stage #1: methyl 4-chlorocinnamate With nickel(II) triflate; C47H72N4O4 In dichloromethane at 35℃; for 0.5h; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In dichloromethane at -20℃; Inert atmosphere; enantioselective reaction;	95%

2,5-Dimethylpyrrole (625-84-3) + 3-methoxy-cinnamic acid methyl ester (15854-56-5) → methyl 4-(2,5-dimethyl-1H-pyrrol-3-yl)-4-(3-methoxyphenyl)-2-oxobutanoate

Conditions	Yield
Stage #1: 3-methoxy-cinnamic acid methyl ester With nickel(II) triflate; C47H72N4O4 In dichloromethane at 35℃; for 0.5h; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In dichloromethane at -20℃; Inert atmosphere; enantioselective reaction;	95%

2,5-Dimethylpyrrole (625-84-3) + methyl 3-(thiophen-2-yl)acrylate (20883-96-9) → methyl 4-(2,5-dimethyl-1H-pyrrol-3-yl)-2-oxo-4-(thiophen-2-yl)butanoate

Conditions	Yield
Stage #1: methyl 3-(thiophen-2-yl)acrylate With nickel(II) triflate; C47H72N4O4 In dichloromethane at 35℃; for 0.5h; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In dichloromethane at -20℃; Inert atmosphere; enantioselective reaction;	95%

2,5-Dimethylpyrrole (625-84-3) + methyl 3-(furan-2-yl)acrylate → methyl 4-(2,5-dimethyl-1H-pyrrol-3-yl)-4-(furan-2-yl)-2-oxobutanoate

Conditions	Yield
Stage #1: methyl 3-(furan-2-yl)acrylate With nickel(II) triflate; C47H72N4O4 In dichloromethane at 35℃; for 0.5h; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In dichloromethane at -20℃; Inert atmosphere; enantioselective reaction;	95%

2,5-Dimethylpyrrole (625-84-3) + (2E,4E)-5-Phenyl-penta-2,4-dienoic acid methyl ester (420089-28-7) → methyl (E)-4-(2,5-dimethyl-1H-pyrrol-3-yl)-2-oxo-6-phenylhex-5-enoate

Conditions	Yield
Stage #1: (2E,4E)-5-Phenyl-penta-2,4-dienoic acid methyl ester With nickel(II) triflate; C47H72N4O4 In dichloromethane at 35℃; for 0.5h; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In dichloromethane at -20℃; Inert atmosphere; enantioselective reaction;	95%

2,5-Dimethylpyrrole (625-84-3) + 1,4-phenylenediamine (106-50-3) → 1-amino-4-(2,5-dimethylpyrrol-1-yl)benzene (60176-19-4)

Conditions	Yield
With indium(III) tris[bis(trifluoromethanesulfonyl)amide] In 1,4-dioxane at 120℃; for 48h; Concentration; Schlenk technique; Inert atmosphere;	95%

2,5-Dimethylpyrrole (625-84-3) + aniline (62-53-3) → (E)-2,5-dimethyl-3-(phenyldiazenyl)-1H-pyrrole

Conditions	Yield
Stage #1: aniline With hydrogenchloride In water at 0℃; for 0.0833333h; Stage #2: With sodium nitrite In water at 0℃; for 1h; Stage #3: 2,5-Dimethylpyrrole In pyridine; methanol; water at 0℃; for 1h;	95%

2,5-Dimethylpyrrole (625-84-3) + methyl 4-chlorocinnamate (7560-44-3, 20754-21-6, 20754-24-9) → methyl 4-(4-chlorophenyl)-4-(2,5-dimethyl-1H-pyrrol-3-yl)-2-oxobutanoate

Conditions	Yield
Stage #1: methyl 4-chlorocinnamate With nickel(II) triflate; C43H64N4O4 In toluene at 35℃; for 0.5h; Friedel-Crafts Alkylation; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In toluene at -20℃; Friedel-Crafts Alkylation; Inert atmosphere; enantioselective reaction;	94%

2,5-Dimethylpyrrole (625-84-3) + methyl 3-(furan-2-yl)acrylate → methyl 4-(2,5-dimethyl-1H-pyrrol-3-yl)-4-(furan-2-yl)-2-oxobutanoate

Conditions	Yield
Stage #1: methyl 3-(furan-2-yl)acrylate With nickel(II) triflate; C43H64N4O4 In toluene at 35℃; for 0.5h; Friedel-Crafts Alkylation; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In toluene at -20℃; Friedel-Crafts Alkylation; Inert atmosphere; enantioselective reaction;	94%

2,5-Dimethylpyrrole (625-84-3) + diethyl ether (60-29-7) + dimethylaluminum chloride (1184-58-3) → C12H24AlNO

Conditions	Yield
Stage #1: 2,5-Dimethylpyrrole; diethyl ether With n-butyllithium In hexane at -78 - 20℃; Inert atmosphere; Glovebox; Schlenk technique; Stage #2: dimethylaluminum chloride In diethyl ether; hexane at -78℃; Inert atmosphere; Glovebox; Schlenk technique;	94%

2,5-Dimethylpyrrole (625-84-3) + bis(trimethylsilyl)amido(pentaisopropylcyclopentadienyl)iron(II) → 2,5-dimethylpyrrolyl(pentaisopropylcyclopentadienyl)iron(II)

Conditions	Yield
In pentane at 20℃; for 20h; Inert atmosphere;	94%

2,5-Dimethylpyrrole (625-84-3) + bromobenzene (108-86-1) → 2-phenyl-2,5-dimethyl-2H-pyrrole

Conditions	Yield
Stage #1: 2,5-Dimethylpyrrole With n-butyllithium at 0℃; for 0.25h; Inert atmosphere; Stage #2: bromobenzene With bis(dibenzylideneacetone)-palladium(0); ruphos at 100℃; Inert atmosphere;	94%

2,5-Dimethylpyrrole (625-84-3) + 1-bromo-4-methoxy-benzene (104-92-7) → 2-(4-methoxyphenyl)-2,5-dimethyl-2H-pyrrole

Conditions	Yield
Stage #1: 2,5-Dimethylpyrrole With n-butyllithium at 0℃; for 0.25h; Inert atmosphere; Stage #2: 1-bromo-4-methoxy-benzene With bis(dibenzylideneacetone)-palladium(0); ruphos at 100℃; for 12h; Inert atmosphere; regioselective reaction;	94%

2,5-Dimethylpyrrole (625-84-3) + methyl ester of m-chlorocinnamic acid (42175-03-1) → methyl 4-(3-chlorophenyl)-4-(2,5-dimethyl-1H-pyrrol-3-yl)-2-oxobutanoate

Conditions	Yield
Stage #1: methyl ester of m-chlorocinnamic acid With nickel(II) triflate; C47H72N4O4 In dichloromethane at 35℃; for 0.5h; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In dichloromethane at -20℃; Inert atmosphere; enantioselective reaction;	93%

2,5-Dimethylpyrrole (625-84-3) + methyl 3-(4-methylphenyl)acrylate (7560-43-2, 20754-20-5, 50363-84-3) → methyl 4-(2,5-dimethyl-1H-pyrrol-3-yl)-2-oxo-4-(p-tolyl)butanoate

Conditions	Yield
Stage #1: methyl 3-(4-methylphenyl)acrylate With nickel(II) triflate; C47H72N4O4 In dichloromethane at 35℃; for 0.5h; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In dichloromethane at -20℃; Inert atmosphere; enantioselective reaction;	93%

2,5-Dimethylpyrrole (625-84-3) + 4-iodoanisol (529-28-2) → 2-(2-methoxyphenyl)-2,5-dimethyl-2H-pyrrole

Conditions	Yield
Stage #1: 2,5-Dimethylpyrrole With n-butyllithium at 0℃; for 0.25h; Inert atmosphere; Stage #2: 4-iodoanisol With bis(dibenzylideneacetone)-palladium(0); ruphos at 100℃; for 12h; Inert atmosphere;	93%

2,5-Dimethylpyrrole (625-84-3) + tetrakis(dimethylamido)titanium(IV) → Ti(σ-2,5-dimethylpyrrolyl)(NMe2)3 (1202170-29-3)

Conditions	Yield
In toluene under Ar, Schlenk techniques; soln. of dimethylpyrrole in toluene added dropwise into cooled (-50°C) and stirred Ti(NMe2)4 in toluene, yellow soln. turned orange during react., warming to room temp., stirring overnight; volatiles removed in vac., recrystn. (hexane, -80°C), filtered, dried (vac.); elem. anal.;	92%

2,5-Dimethylpyrrole (625-84-3) + p-Phenyl-zimtsaeuremethylester (20883-99-2) → methyl 4-([1,1'-biphenyl]-4-yl)-4-(2,5-dimethyl-1H-pyrrol-3-yl)-2-oxobutanoate

Conditions	Yield
Stage #1: p-Phenyl-zimtsaeuremethylester With nickel(II) triflate; C43H64N4O4 In toluene at 35℃; for 0.5h; Friedel-Crafts Alkylation; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In toluene at -20℃; Friedel-Crafts Alkylation; Inert atmosphere; enantioselective reaction;	92%

2,5-Dimethylpyrrole (625-84-3) + 3,4-Dichlor-zimtsaeure-methylester (20883-95-8) → methyl 4-(3,4-dichlorophenyl)-4-(2,5-dimethyl-1H-pyrrol-3-yl)-2-oxobutanoate

Conditions	Yield
Stage #1: 3,4-Dichlor-zimtsaeure-methylester With nickel(II) triflate; C47H72N4O4 In dichloromethane at 35℃; for 0.5h; Inert atmosphere; Stage #2: 2,5-Dimethylpyrrole In dichloromethane at -20℃; Inert atmosphere; enantioselective reaction;	92%

2,5-Dimethylpyrrole (625-84-3) + sodium 4-methylbenzenesulfinate (824-79-3) → 2,5-dimethyl-3,4-bis(p-tolylthio)-1H-pyrrole

Conditions	Yield
With hydrogenchloride; 1-hexyl-3-methyl-1-imidazolium bromide In water at 80℃; for 6h; chemoselective reaction;	92%

Upstream product

• 3378-71-0 2,5-dimethylpyrrolide 
• 625-86-5 2,5-dimethylfuran 
• 97142-87-5 1-formyl-2,5-dimethyl-pyrrole 
• 110-13-4 2,5-hexanedione 
• 50-99-7 D-glucose 
• 56-40-6 glycine 
• 534-60-1 5-carboxymethyl-2-methyl-furan-3-carboxylic acid 
• 74-88-4 methyl iodide 
• 90222-74-5 2,5-dimethyl-1H-pyrrole-3,4-dicarboxylic acid 
• 60-29-7 diethyl ether 
• 67-56-1 methanol 
• 7664-41-7 ammonia 
• 74-99-7 prop-1-yne 
• 127-06-0 acetone oxime 

Downstream Products

• 1500-94-3 3-acetyl-2,5-dimethylpyrrole 
• 5435-88-1 3,4-bis-dimethylaminomethyl-2,5-dimethyl-pyrrole 
• 2405-06-3 3-chloro-2,6-dimethylpyridine 
• 2199-63-5 2,5-dimethylpyrrole-3-carbaldehyde 
• 3430-31-7 3-bromo-2,6-dimethylpyridine 
• 109568-92-5 2,5-dimethyl-pyrrole-3-carbothioic acid anilide 
• 56139-74-3 2,5-dimethyl-1H-pyrrole-3,4-dicarbaldehyde 
• 76160-66-2 hexane-2,5-dione bis-p-nitrophenylhydrazone 
• 4815-48-9 hexane-2,5-dione-mono-(2,4-dinitro-phenylhydrazone) 
• 1003-90-3 2,3,4,5-tetramethylpyrrole 
• 90154-81-7 2,2,4,5-tetramethyl-2H-pyrrole 
• 26458-30-0 pentamethyl-2H-pyrrole 
• 122546-85-4 2,2,3,5-tetramethyl-2H-pyrrole 
• 822-64-0 2,5-dimethyl-1-pyrroline 

Relevant articles and documents

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An improved method for the preparation of N-unsubstituted 1,4,5,6-tetrahydrocyclopenta[b]pyrroles: Synthesis of an azaprostacyclin analogue and its 7-cyano derivative

Paal-Knorr cyclization of 2-acetonylcyclopentanone derivatives can be carried out most efficiently by reaction with hexamethyldisilazane (HMDS) when the reagents are previously adsorbed on alumina. By this procedure, the unstable pyrroloprostacyclin derivative rac-6a has been synthesized in 66% yield from racemic 6-oxoprostaglandin E1 (rac)-5b. In order to obtain less sensitive pyrroloprostacyclin derivatives, rac-6a has been transformed into the stable nitriles rac-7a and rac-7b by cyanation of the pyrrole ring with chlorosulfonyl isocyanate in the presence of triethylamine and subsequent cleavage of the protecting groups, respectively.

Thermal Behavior Analysis of Two Synthesized Flavor Precursors of N-alkylpyrrole Derivatives

To expand the library of pyrrole-containing flavor precursors, two new flavor precursors—methyl N-benzyl-2-methyl-5-formylpyrrole-3-carboxylate (NBMF) and methyl N-butyl-2-methyl-5-formylpyrrole-3-carboxylate (NUMF)—were synthesized by cyclization, oxidation, and alkylation reactions. Thermogravimetry (TG), differential scanning calorimeter, and pyrolysis–gas chromatography/mass spectrometry were utilized to analyze the thermal degradation behavior and thermal degradation products of NBMF and NUMF. The TG-DTG curve indicated that the maximum mass loss rates of NBMF and NUMF appear at 310 and 268°C, respectively. The largest peaks of NBMF and NUMF showed by the differential scanning calorimeter curve were 315 and 274°C, respectively. Pyrolysis–gas chromatography/mass spectrometry detected small molecule fragrance compounds appeared during thermal degradation, such as 2-methylpyrrole, 1-methylpyrrole-2-carboxylic acid methyl ester, limonene, and methyl formate. Finally, the thermal degradation mechanism of NBMF and NUMF was discussed, which provided a theoretical basis for their application in tobacco flavoring additives.

Acceptorless Dehydrogenative Coupling Using Ammonia: Direct Synthesis of N-Heteroaromatics from Diols Catalyzed by Ruthenium

The synthesis of N-heteroaromatic compounds via an acceptorless dehydrogenative coupling process involving direct use of ammonia as the nitrogen source was explored. We report the synthesis of pyrazine derivatives from 1,2-diols and the synthesis of N-substituted pyrroles by a multicomponent dehydrogenative coupling of 1,4-diols and primary alcohols with ammonia. The acridine-based Ru-pincer complex 1 is an effective catalyst for these transformations, in which the acridine backbone is converted to an anionic dearomatized PNP-pincer ligand framework.