500-05-0

Basic information

• Product Name: Coumalic acid
• Synonyms: 2-Oxo-2H-pyran-5-carboxylic acid, 2-Pyrone-5-carboxylic acid;6-Oxopyran-3-carboxylic acid;a-Pyrone-5-carboxylic acid;α-Pyrone-5-carboxylic acid;Coumalic acid, 5-Carboxy-2-pyrone;courMaric acid;2H-Pyran-5-carboxylic acid, 2-oxo;Cumalic Acid alpha-Pyrone-5-carboxylic Acid
• CAS NO: 500-05-0
• Molecular Formula: C₆H₄O₄
• Molecular Weight: 140.09
• EINECS: 207-899-0
• Product Categories: sy
• Mol File: 500-05-0.mol
• Article Data: 10

Chemical Properties

• Melting Point: 203-205 °C (dec.)(lit.)
• Boiling Point: 218 °C120 mm Hg(lit.)
• Flash Point: 218°C/120mm
• Appearance: pale yellow to pale brown powder
• Density: 1.2154 (rough estimate)
• Vapor Pressure: 0.000881mmHg at 25°C
• Refractive Index: 1.4434 (estimate)
• Storage Temp.: Sealed in dry,Room Temperature
• PKA: 2.80±0.20(Predicted)
• Water Solubility: Very soluble in water.
• Merck: 14,2557
• BRN: 119747
• CAS DataBase Reference: Coumalic acid(CAS DataBase Reference)
• NIST Chemistry Reference: Coumalic acid(500-05-0)
• EPA Substance Registry System: Coumalic acid(500-05-0)

Safety Data

• Hazard Codes: Xi
• Safety Statements: 22-24/25
• WGK Germany: 3
• TSCA: Yes
• Hazardous Substances Data: 500-05-0(Hazardous Substances Data)

Usage

Chemical Properties

pale yellow to pale brown powder

Uses

Coumalic acid undergoes thermal reaction with 1,3-butadiene to yield dimethyl tricycle[3.2.1.02,7]oct-3-ene-2,4-dicarboxylate.

General Description

Decarboxylates to α-pyrone, a Diels-Alder diene.

Purification Methods

The acid crystallises from MeOH. The methyl ester has m 73-74o (from pet ether) and b 178-180o/60 mm. [Beilstein 18/8 V 120.]

InChI:InChI=1/C6H4O4/c7-5-2-1-4(3-10-5)6(8)9/h1-3H,(H,8,9)/p-1

Synthetic route

methyl coumalate (6018-41-3) → 2H-pyran-2-one-5-carboxylic acid (500-05-0)

Conditions	Yield
With iodine; aluminium In acetonitrile at 80℃; for 18h;	90%

(S)-Malic acid (97-67-6) → 2H-pyran-2-one-5-carboxylic acid (500-05-0)

Conditions	Yield
With trifluorormethanesulfonic acid In 1,2-dichloro-ethane at 100℃; Reagent/catalyst; Temperature; Solvent; regioselective reaction;	86%

malic acid (617-48-1) → 2H-pyran-2-one-5-carboxylic acid (500-05-0)

Conditions	Yield
With sulfuric acid at 80 - 90℃; for 3h;	85%
With sulfuric acid Heating;	67%
Stage #1: malic acid With fuming sulphuric acid In sulfuric acid at 75℃; for 6h; Stage #2: In ice-cold water at 10℃; for 24h;	65%

(S)-Malic acid (97-67-6) → 2H-pyran-2-one-5-carboxylic acid (500-05-0) + (2E)-but-2-enedioic acid (110-17-8)

Conditions	Yield
With methanesulfonic acid In 1,2-dichloro-ethane at 100℃; Reagent/catalyst; Temperature; Solvent;	A 14% B 25%

(S)-Malic acid (97-67-6) + (E)-3-Ureido-but-2-enoic acid ethyl ester (5435-44-9, 22243-66-9) → 2H-pyran-2-one-5-carboxylic acid (500-05-0) + 3-oxopropanoic acid (926-61-4)

sodium formylacetic acid ester → 2H-pyran-2-one-5-carboxylic acid (500-05-0)

Conditions	Yield
With sulfuric acid

(S)-Malic acid (97-67-6) + sulfuric acid (7664-93-9) → 2H-pyran-2-one-5-carboxylic acid (500-05-0)

methyl 4-carbomethoxy-5-methoxy-penta-2(E),4(Z)-dienoate (114106-77-3) + hydrogen bromide (10035-10-6, 12258-64-9) → 2H-pyran-2-one-5-carboxylic acid (500-05-0)

4-formyl-pentenedioic acid dimethyl ester + hydrogen bromide (10035-10-6, 12258-64-9) → 2H-pyran-2-one-5-carboxylic acid (500-05-0)

Conditions	Yield
Kochen;

sulfuric acid (7664-93-9) + sodium 3-ethoxy-3-oxoprop-1-en-1-olate → 2H-pyran-2-one-5-carboxylic acid (500-05-0)

(S)-Malic acid (97-67-6) + sulfuric acid (7664-93-9) → 2H-pyran-2-one-5-carboxylic acid (500-05-0) + 3-oxopropanoic acid (926-61-4)

2H-pyran-2-one-5-carboxylic acid (500-05-0) + ethene (74-85-1) → C8H8O4

Conditions	Yield
In 1,4-dioxane at 110℃; for 16h; Kinetics; Temperature; Diels-Alder Cycloaddition;	98%

2H-pyran-2-one-5-carboxylic acid (500-05-0) → 6-oxo-tetrahydro-pyran-3-carboxylic acid (5807-38-5)

Conditions	Yield
With Raney nickel In methanol; toluene under 760.051 Torr; for 6h;	96.8%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + S-(1-butyn-3-yl)-O-methyl xanthate → methyl coumalate (6018-41-3)

Conditions	Yield
In toluene Heating;	92%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + trimethyl orthoformate (149-73-5) → methyl 4-carbomethoxy-5-methoxy-penta-2(E),4(Z)-dienoate (114106-77-3) + methyl 3,5-dimethoxy-4-carbomethoxypent-4-enoate (114106-78-4)

Conditions	Yield
With sulfuric acid In methanol for 48h; Heating;	A 89% B 6%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + tenofovir disoproxil → tenofovir disoproxil coumalate

Conditions	Yield
In hexane; dichloromethane at 20 - 40℃; Solvent; Temperature;	89%

2H-pyran-2-one-5-carboxylic acid (500-05-0) → 2-oxo-2H-pyran-5-carbonyl chloride (23090-18-8)

Conditions	Yield
With phosphorus pentachloride at 60℃; for 1h;	86%
With thionyl chloride at 100℃; for 8h;	84%
With phosphorus pentachloride at 60℃; for 1h;	80%

maleic anhydride (108-31-6) + 2H-pyran-2-one-5-carboxylic acid (500-05-0) → bicyclo<2.2.2>oct-2-en-2,5-exo,6exo,7exo,8exo-pentacarbonsaeure-5,6:7,8-dianhydrid (77802-48-3)

Conditions	Yield
at 200℃;	86%
at 200℃;	65%
at 200℃; Heating;

2H-pyran-2-one-5-carboxylic acid (500-05-0) + ethanol (64-17-5) → 2-Oxo-2H-pyran-5-carbonseaure-ethylester (5942-96-1)

Conditions	Yield
With dmap; dicyclohexyl-carbodiimide In dichloromethane for 18h; Ambient temperature;	86%
With trifluoromethylsulfonic anhydride; triethylamine; Triphenylphosphine oxide In 1,2-dichloro-ethane at 25℃; for 0.25h;	78%

1-Heptene (592-76-7) + 2H-pyran-2-one-5-carboxylic acid (500-05-0) → 4-pentylbenzoic acid (26311-45-5)

Conditions	Yield
With palladium 10% on activated carbon In 1,3,5-trimethyl-benzene at 200℃; Diels-Alder reaction; regioselective reaction;	85%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + 2-(2-chloro-4-(4-chlorobenzoyl)-6-fluorophenoxy)acetohydrazide (1443038-08-1) → [2-4-(4-chloro)benzoyl-2-chloro-6-fluorophenoxy]aceto-N(pyrone-2-one)carbonyl hydrazide

Conditions	Yield
Stage #1: 2-(2-chloro-4-(4-chlorobenzoyl)-6-fluorophenoxy)acetohydrazide With 2,6-dimethylpyridine In dichloromethane at 25 - 30℃; for 0.5h; Stage #2: 2H-pyran-2-one-5-carboxylic acid With O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate In dichloromethane at 0 - 5℃; for 0.5h;	85%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + cyclopropanecarboxylic acid (3-amino-1H-pyrazolo[3,4-d]thiazol-5-yl)-amide, trifluoroacetic acid (937037-30-4) → 1-[5-(cyclopropanecarbonyl-amino)-1H-pyrazolo[3,4-d]thiazol-3-yl]-6-oxo-1,6-dihydro-pyridine-3-carboxylic acid

Conditions	Yield
With pyridine at 20℃; for 8h;	82%

methanol (67-56-1) + 2H-pyran-2-one-5-carboxylic acid (500-05-0) → methyl coumalate (6018-41-3)

Conditions	Yield
for 3h; Reflux;	81.8%
With sulfuric acid for 1h; Heating;	55%
With sulfuric acid

2H-pyran-2-one-5-carboxylic acid (500-05-0) + 2-(4-benzoylphenoxy)acetohydrazide (670221-21-3) → 2-(4-benzoylphenoxy)aceto-N(pyrone-2-one)carbonylhydrazide

Conditions	Yield
Stage #1: 2-(4-benzoylphenoxy)acetohydrazide With 2,6-dimethylpyridine In dichloromethane at 25 - 30℃; for 0.5h; Stage #2: 2H-pyran-2-one-5-carboxylic acid With O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate In dichloromethane at 0 - 5℃; for 0.5h;	81%

2H-pyran-2-one-5-carboxylic acid (500-05-0) → C6H3ClO4

Conditions	Yield
	80%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + tetrakis[bis(trimethylsilyl)methyl]digallane(4) (125370-09-4) → Ga2(CH(SiMe3)2)2(2-oxo-2H-pyran-5-carboxylate)2 (1258211-75-4)

Conditions	Yield
In tetrahydrofuran digallium compd. and acid suspended in THF at room temp.; suspn. stirred at room temp. for 16 h; volatiles removed in vacuo; residue washed with n-pentane;	79%

allylbenzene (300-57-2) + 2H-pyran-2-one-5-carboxylic acid (500-05-0) → 4-Benzylbenzoic acid (620-86-0)

Conditions	Yield
With palladium 10% on activated carbon In 1,3,5-trimethyl-benzene at 200℃; Diels-Alder reaction; regioselective reaction;	79%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + 2-[4-(4-methylbenzoyl)-2-chloro-6-fluorophenoxy]acethydrazide (1443038-11-6) → [2-4(-4-methyl)benzoyl-2-chloro-6-fluorophenoxy]aceto-N-(pyrone-2-one)carbonylhydrazide

Conditions	Yield
Stage #1: 2-[4-(4-methylbenzoyl)-2-chloro-6-fluorophenoxy]acethydrazide With 2,6-dimethylpyridine In dichloromethane at 25 - 30℃; for 0.5h; Stage #2: 2H-pyran-2-one-5-carboxylic acid With O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate In dichloromethane at 0 - 5℃; for 0.5h;	78%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + Dithiocarbonic acid O-[(3S,5S,8R,9S,10S,13R,14S,17R)-17-((R)-1,5-dimethyl-hexyl)-10,13-dimethyl-hexadecahydro-cyclopenta[a]phenanthren-3-yl] ester S-prop-2-ynyl ester (165452-00-6) → 6-Oxo-6H-pyran-3-carboxylic acid (3R,5S,8R,9S,10S,13R,14S,17R)-17-((R)-1,5-dimethyl-hexyl)-10,13-dimethyl-hexadecahydro-cyclopenta[a]phenanthren-3-yl ester

Conditions	Yield
In toluene Heating;	77%

diazomethane (186581-53-3, 908094-01-9) + 2H-pyran-2-one-5-carboxylic acid (500-05-0) → methyl coumalate (6018-41-3)

Conditions	Yield
In tetrahydrofuran; diethyl ether at 20℃; for 3h;	76.4%

2H-pyran-2-one-5-carboxylic acid (500-05-0) → 5-bromo-2H-pyran-2-one (19978-33-7) + 3,5-dibromo-2H-pyran-2-one (19978-41-7)

Conditions	Yield
With N-Bromosuccinimide; lithium acetate; tetrabutylammomium bromide In tetrachloromethane; acetonitrile at 65℃;	A n/a B 76%
With N-Bromosuccinimide; lithium acetate In water; acetonitrile at 20℃; for 72h; Product distribution; Further Variations:; Reaction partners; reagents ratios; Hundsdiecker reaction;	A 35% B 15%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + 1-Decene (872-05-9) → 4-octylbenzoic acid (3575-31-3)

Conditions	Yield
With palladium 10% on activated carbon In 1,3,5-trimethyl-benzene at 200℃; Diels-Alder reaction; regioselective reaction;	72%
With palladium on activated charcoal In 1,3,5-trimethyl-benzene at 200℃; Diels-Alder Cycloaddition; Sealed tube;	72%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + [2-chloro-6-fluoro-4-(4-fluoro-benzoyl)-phenoxy]acetic acid hydrazide (1443038-07-0) → [2-4-(4-fluoro)benzoyl-2-chloro-6-fluorophenoxy]aceto-N-(pyrone-2-one)carbonylhydrazide

Conditions	Yield
Stage #1: [2-chloro-6-fluoro-4-(4-fluoro-benzoyl)-phenoxy]acetic acid hydrazide With 2,6-dimethylpyridine In dichloromethane at 25 - 30℃; for 0.5h; Stage #2: 2H-pyran-2-one-5-carboxylic acid With O-(benzotriazol-1-yl)-N,N,N',N'-tetramethyluronium tetrafluoroborate In dichloromethane at 0 - 5℃; for 0.5h;	72%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + 1-methoxy-5,6,7,8-tetrafluorobenzobenzobarrelene (14111-43-4) → benzoic acid (65-85-0)

Conditions	Yield
In xylene at 200 - 205℃; for 4h; Product distribution; var. temp. and time;	71%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + propene (187737-37-7) → p-Toluic acid (99-94-5) + m-Toluic acid (99-04-7)

Conditions	Yield
With palladium 10% on activated carbon; hydrogen; 5-methyl-dihydro-furan-2-one In toluene at 180℃; under 6723.1 Torr; for 8h; Reagent/catalyst; Solvent; Temperature; Time;	A 70.8% B 15.8%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + benzyl alcohol (100-51-6) → coumalic acid benzyl ester (61752-10-1)

Conditions	Yield
With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In tetrahydrofuran; dichloromethane at 20℃; for 5h;	70%
With 8-aminopyrene-1,3,6-trisulfonic acid, trisodium salt for 15h; Heating;

2H-pyran-2-one-5-carboxylic acid (500-05-0) + 1-undecene (821-95-4) → 4-n-Nonylbenzoic acid (38289-46-2)

Conditions	Yield
With palladium 10% on activated carbon In 1,3,5-trimethyl-benzene at 200℃; Diels-Alder reaction; regioselective reaction;	69%

2H-pyran-2-one-5-carboxylic acid (500-05-0) + 1-(allyloxy)heptane (16519-24-7) → 4-((heptyloxy)methyl)benzoic acid (173265-17-3)

Conditions	Yield
With palladium 10% on activated carbon In 1,3,5-trimethyl-benzene at 200℃; Diels-Alder reaction; regioselective reaction;	66%

Upstream product

• 97-67-6 (S)-Malic acid 
• 5435-44-9 (E)-3-Ureido-but-2-enoic acid ethyl ester 
• 617-48-1 malic acid 
• 7664-93-9 sulfuric acid 
• 6018-41-3 methyl coumalate 
• 10035-10-6 hydrogen bromide 
• 114106-77-3 methyl 4-carbomethoxy-5-methoxy-penta-2(E),4(Z)-dienoate 

Downstream Products

• 5942-96-1 2-Oxo-2H-pyran-5-carbonseaure-ethylester 
• 97507-42-1 ethyl (2E)-4-ethoxycarbonyl-5-ethoxy-2,4-pentadienoate 
• 64-18-6 formic acid 
• 1724-02-3 glutaconic acid 
• 61752-10-1 coumalic acid benzyl ester 
• 19978-33-7 5-bromo-2H-pyran-2-one 
• 19978-32-6 3-bromo-2H-pyran-2-one 
• 19978-41-7 3,5-dibromo-2H-pyran-2-one 
• 99-94-5 p-Toluic acid 
• 99-04-7 m-Toluic acid 
• 31673-50-4 4-methyl-1,5-cyclohexadiene-1-carboxylic acid 

Relevant articles and documents

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Synthesis method of methyl coumalate

The invention discloses a synthesis method of methyl coumalate. The synthesis method comprises the following steps: adding water-containing sulfuric acid into a kettle, stirring, heating to a temperature of less than 100 DEG C, and adding a pre-prepared saturated malic acid solution in a dropwise manner; carrying out a constant-temperature reaction after the adding, and monitoring the reaction process by using gas chromatography until the malic acid reaction is finished; stopping the stirring, layering, cooling to below 50 DEG C, and separating out a lower layer sulfuric acid aqueous solution;continuously stirring, heating to reflux, and adding a large amount of methanol in a dropwise manner; carrying out a reflux reaction for a certain time, and carrying out gas phase monitoring until coumalic acid disappears; evaporating out most of the solvent to form a slurry in the system, cooling to room temperature, and adding an aqueous solution of an alkaline compound in a dropwise manner toform a large amount of precipitates; and filtering, washing with water, and drying to obtain the methyl coumalate.

Four hydrogen pyrane two fluorine Asia armor propoxycyclohexyl linking group containing a liquid crystal compound, preparation method and application thereof

The invention discloses a liquid crystal compound containing a tetrahydropyrane difluoro methoxy-linking group and a preparation method and application thereof. The liquid crystal compound is represented by a formula I. In a molecular structure of the compound represented by the formula I, the liquid crystal compound containing the tetrahydropyrane difluoro methoxy-linking group (img file='DDA0000475765100000011. TIF' wi='384' he='112'/) has high dielectric anisotropy. What's more important is that the liquid crystal compound further has high response speed and clearing points and low rotational viscosity. Compared with blended liquid crystal compounds, the liquid crystal compound has very important significance. As the formula I, (img file='DDA0000475765100000012. TIF' wi='984' he='256'/).