940-07-8

Basic information

• Product Name: PYRAZINE-2,6-DICARBOXYLIC ACID
• Synonyms: AKOS 90649;PYRAZINE-2,6-DICARBOXYLIC ACID;2,6-Pyrazinedicarboxylic acid
• CAS NO: 940-07-8
• Molecular Formula: C₆H₄N₂O₄
• Molecular Weight: 168.10696
• Mol File: 940-07-8.mol
• Article Data: 1

Chemical Properties

• Melting Point: 225℃
• Boiling Point: 491.3±45.0 °C(Predicted)
• Appearance: /
• Density: 1.665±0.06 g/cm3 (20 ºC 760 Torr)
• Storage Temp.: 2-8°C
• PKA: 2.24±0.10(Predicted)
• CAS DataBase Reference: PYRAZINE-2,6-DICARBOXYLIC ACID(CAS DataBase Reference)
• NIST Chemistry Reference: PYRAZINE-2,6-DICARBOXYLIC ACID(940-07-8)
• EPA Substance Registry System: PYRAZINE-2,6-DICARBOXYLIC ACID(940-07-8)

Safety Data

• Hazardous Substances Data: 940-07-8(Hazardous Substances Data)

Usage

General Description

PYRAZINE-2,6-DICARBOXYLIC ACID, also known as quinoxaline-1,4-dicarboxylic acid or PDC, is a type of pyrazine carboxylic acid. This chemical compound is a heterocyclic organic compound displaying aromatic properties and contains two carbonyl groups. The pyrazine ring in this chemical is a basic structure that is a common part of various pharmaceutical agents. Its derivatives exhibit a variety of pharmacological properties and are used in the synthesis of a number of therapeutic agents including antitumor, antifungal, antimicrobial, and anti-inflammatory agents. Additionally, PDC is used in the preparation of polymers, dyes, and pesticides.

Synthetic route

dimethyl pyrazine-2,6-dicarboxylate (35042-26-3) → pyrazine-2,6-dicarboxylic acid (940-07-8)

Conditions	Yield
Stage #1: dimethyl pyrazine-2,6-dicarboxylate With sodium hydroxide In tetrahydrofuran; water for 1h; Stage #2: With hydrogenchloride In tetrahydrofuran; water	100%

pyrazine-2,6-dicarbonitrile (70911-23-8) → pyrazine-2,6-dicarboxylic acid (940-07-8)

Conditions	Yield
With sodium hydroxide

2,3,5-pyrazine-tricarboxylic acid (23046-95-9) → pyrazine-2,6-dicarboxylic acid (940-07-8) + 2,5-pyrazinedicarboxylic acid (122-05-4)

Conditions	Yield
With water

2,3,5-pyrazine-tricarboxylic acid (23046-95-9) → pyrazine-2,6-dicarboxylic acid (940-07-8) + diethyl pyrazine-2,5-dicarboxylate (103150-78-3)

Conditions	Yield
With water
With acetic acid

6-chloro-pyrazine-2-carboxylic acid methyl ester (23611-75-8) → pyrazine-2,6-dicarboxylic acid (940-07-8)

Conditions	Yield
Multi-step reaction with 3 steps 1.1: sodium hydride / mineral oil; tetrahydrofuran / 0.5 h 1.2: 20 h / Reflux 2.1: lithium carbonate / 0.5 h 2.2: 3 h / 0 °C 3.1: sodium hydroxide / water; tetrahydrofuran / 1 h View Scheme

C9H6N4O2 → pyrazine-2,6-dicarboxylic acid (940-07-8)

Conditions	Yield
Multi-step reaction with 2 steps 1.1: lithium carbonate / 0.5 h 1.2: 3 h / 0 °C 2.1: sodium hydroxide / water; tetrahydrofuran / 1 h View Scheme

pyrazine-2,6-dicarboxylic acid (940-07-8) + europium(III) oxide + caesium carbonate (534-17-8) → Cs3[Eu(pyrazine-2,6-dicarboxylate)3]*7H2O

Conditions	Yield
In water suspn. Eu2O3 and ligand in water was heated at 80°C for 1 h, Cs2CO3 was added to pH 6.0, allowed to cool to room temp.; soln. was filtered and evapd. to dryness in vacuo, residue was recrystd.rom hot MeOH; elem. anal.;	88%

[2,2]bipyridinyl (366-18-7) + pyrazine-2,6-dicarboxylic acid (940-07-8) + copper(II) acetate dihydrate + water (7732-18-5) → [Cu(pyrazine-2,6-dicarboxylic acid-2H)(2,2'-bipyridine)(H2O)]*2.5H2O

Conditions	Yield
In water High Pressure; mixt. of Cu(OAc)2*2H2O (0.1 mmol), pyrazine-2,6-dicarboxylic acid (0.1 mmol), 2,2'-bipyridine (0.1 mmol) and H2O (5 ml) sealed in Teflon-lined stainless steel reactor (23 ml); heated (140°C, 144 h); cooled to room temp.; crystals washed with deionized H2O; dried in air; elem. anal.;	78%

pyrazine-2,6-dicarboxylic acid (940-07-8) + titanium tetrachloride (7550-45-0) → {TiO(pyrazine-2,6-dicarboxylate)(H2O)2}n

Conditions	Yield
In water dropwise addn. of TiCl4 to a suspn. of the dicarboxylic acid in water with stirring, warming to 50°C for 5 min; filtn. after cooling, ppt. is washed, dried, elem. anal.;	75%

1,2-bis(4'-pyridyl)ethane (4916-57-8) + pyrazine-2,6-dicarboxylic acid (940-07-8) + copper(II) acetate dihydrate + water (7732-18-5) → [Cu2(pyrazine-2,6-dicarboxylic acid-2H)2(1,2-bis(4-pyridyl)-ethane)(H2O)2] (937021-46-0)

Conditions	Yield
With NaOH In water High Pressure; mixt. of Cu(OAc)2*2H2O (0.1 mmol), pyrazine-2,6-dicarboxylic acid (0.1 mmol), 1,2-bis(4-pyridyl)ethane (0.1 mmol), H2O (8 ml) and 0.65 M NaOH (0.15 ml) sealed in Teflon-lined stainless steel reactor (23 ml); heated (100°C, 96 h); cooled to room temp.; crystals washed with deionized H2O; dried in air; elem. anal.;	73%

1,10-Phenanthroline (66-71-7) + pyrazine-2,6-dicarboxylic acid (940-07-8) + zinc(II) acetate dihydrate (5970-45-6) → [Zn(pyrazine-2,6-dicarboxylate)(1,10-phenanthroline)H2O]2 (935730-72-6)

Conditions	Yield
In water High Pressure; mixt. of Zn(OAc)2*2H2O, C4N2H2(COOH)2, phen, and water heated at 140°C for 96 h; cooling to room temp., washing with water, drying in air; elem. anal.;	72%

pyrazine-2,6-dicarboxylic acid (940-07-8) + aquapentaammineruthenium(II) hexafluorophosphate (34843-18-0) + sodium perchlorate → Ru(NH3)5(C4H2N2(COOH)2)(3+)*3ClO4(1-)*H2O=Ru(NH3)5(C4H2N2(COOH)2)(ClO4)3*H2O

Conditions	Yield
With perchloric acid; dihydrogen peroxide In not given complex added to ligand soln. at pH 4 under Ar at 20°C, HClO4 soln. and NaClO4 added, H2O2 soln. added; cooled to 5°C, filtered, crystals washed with EtOH and ether;	70%

pyrazine-2,6-dicarboxylic acid (940-07-8) + bis(acetylacetonate)oxovanadium (3153-26-2) → {VO(pyrazine-2,6-dicarboxylate)(H2O)2}*2H2O

Conditions	Yield
In acetone addn. of VO(acac)2 to a soln. of the dicarboxylic acid in acetone at 40°C; filtn. at 2°C after 15 min., ppt. is washed, dried, elem. anal.;	69%

trisodium hexanitrocobaltate(III) + pyrazine-2,6-dicarboxylic acid (940-07-8) → (PPh4){Co(pyrazine-2,6-dicarboxylate)2}

Conditions	Yield
With H2O2; tetraphenylphosphonium chloride In water addn. of the Co-complex to a soln. of the dicarboxylic acid in water obtained 2 drops H2O2, soln. is warmed to 70°C for 20 min, addn. of drops H2O2 and the phosphonium-salt, cooled to 2°C; filtn., elem. anal.;	68%

[2,2]bipyridinyl (366-18-7) + pyrazine-2,6-dicarboxylic acid (940-07-8) + zinc(II) acetate dihydrate (5970-45-6) → [Zn(pyrazine-2,6-dicarboxylate)(2,2'-bipiridine)H2O]*0.5H2O

Conditions	Yield
In water High Pressure; mixt. of Zn(OAc)2*2H2O, C4N2H2(COOH)2, 2,2'-bipyridine, and water heatedat 140°C for 96 h; cooling to room temp., washing with water, drying in air; elem. anal.;	68%

1,10-Phenanthroline (66-71-7) + pyrazine-2,6-dicarboxylic acid (940-07-8) + copper(II) acetate dihydrate + water (7732-18-5) → [Cu(pyrazine-2,6-dicarboxylic acid-2H)(1,10-phenanthroline)(H2O)]*H2O (937021-44-8)

Conditions	Yield
In water High Pressure; mixt. of Cu(OAc)2*2H2O (0.1 mmol), pyrazine-2,6-dicarboxylic acid (0.1 mmol), 1,10-phenanthroline (0.1 mmol) and H2O (5 ml) sealed in Teflon-lined stainless steel reactor (23 ml); heated (140°C, 96 h); cooled to room temp.; crystals washed with deionized H2O; dried in air; elem. anal.;	67%

pyrazine-2,6-dicarboxylic acid (940-07-8) + uranyl nirate hexahydrate → {uranyl(pyrazine-2,6-dicarboxylate)(H2O)} (1024736-44-4)

Conditions	Yield
In water 50°C; filtn., ppt. is washed, dried, elem. anal.;	66%

pyrazine-2,6-dicarboxylic acid (940-07-8) + aquapentaammineruthenium(II) hexafluorophosphate (34843-18-0) + sodium perchlorate → [Ru(NH3)5(pyrazine-2,6-dicarboxylic acid)](ClO4)2*1.5H2O (91687-31-9)

Conditions	Yield
With perchloric acid In not given complex added to ligand soln. at pH 4 under Ar at 20°C, HClO4 soln. and NaClO4 added, kept for 1 h at 5°C; filtered;	65%

iron(III) chloride hexahydrate + pyrazine-2,6-dicarboxylic acid (940-07-8) → (NH4){Fe(pyrazine-2,6-dicarboxylate)2}*4H2O

Conditions	Yield
With NH4Cl In water 20°C, filtn., addn. of NH4Cl to the filtrate, cooling to 2°C; filtn., ppt. is washed (ethanol, ether), air-dried, elem. anal.;	62%

1,2-bis(4'-pyridyl)ethane (4916-57-8) + pyrazine-2,6-dicarboxylic acid (940-07-8) + zinc(II) acetate dihydrate (5970-45-6) → [(Zn(pyrazine-2,6-dicarboxylate)(H2O)2)2(μ-1,2-bis(4-pyridyl)ethane]*1.75H2O

Conditions	Yield
In water High Pressure; mixt. of Zn(OAc)2*2H2O, C4N2H2(COOH)2, 1,2-bis(4-pyridyl)ethane, and water heated at 140°C for 96 h; cooling to room temp., washing with water, drying in air; elem. anal.;	59%

pyrazine-2,6-dicarboxylic acid (940-07-8) + europium(III) oxide + water (7732-18-5) + copper(II) oxide → [EuCu(pyrazine-2,6-dicarboxylate)3][Eu(water)9]0.5[H(water)7]0.5

Conditions	Yield
In water; isopropyl alcohol High Pressure; heating mixture of europium compd., copper compd., pyrazine deriv., water and isopropanol at 180°C for 96 h; elem. anal.;	57.8%

pyrazine-2,6-dicarboxylic acid (940-07-8) + neodymium(III) oxide + water (7732-18-5) → [Nd2(pyrazine-2,6-dicarboxylic acid(-2H))3(H2O)2]*2.5H2O

Conditions	Yield
With 4,4'-bpy*2H2O In water; isopropyl alcohol High Pressure; Nd2O3, 3 equiv. organic ligand, 2 equiv. 4,4'-bpy, water and isopropanolsealed in autoclave; heated at 180°C for 5 days; cooled slowly t o room temp.; elem. anal.;	45%

gadolinium(III) oxide + pyrazine-2,6-dicarboxylic acid (940-07-8) + water (7732-18-5) + copper(II) oxide → [GdCu(pyrazine-2,6-dicarboxylate)3][Gd(water)9]0.5[H(water)7]0.5

Conditions	Yield
In water; isopropyl alcohol High Pressure; heating mixture of gadolinium compd., copper compd., pyrazine deriv., water and isopropanol at 180°C for 96 h; elem. anal.;	44.6%

pyrazine-2,6-dicarboxylic acid (940-07-8) + europium(III) oxide + water (7732-18-5) → [Eu2(pyrazine-2,6-dicarboxylic acid(-2H))3(H2O)2]*2.5H2O

Conditions	Yield
With 4,4'-bpy*2H2O In ethanol; water High Pressure; Nd2O3, 3 equiv. organic ligand, 2 equiv. 4,4'-bpy, water and ethanol sealed in autoclave; heated at 180°C for 5 days; cooled slowly to room temp.; elem. anal.;	43%

lanthanum(III) oxide + pyrazine-2,6-dicarboxylic acid (940-07-8) + water (7732-18-5) + copper(II) oxide → [LaCu(pyrazine-2,6-dicarboxylate)3][La(water)9]0.5[H(water)7]0.5

Conditions	Yield
In water; isopropyl alcohol High Pressure; heating mixture of lanthanum compd., copper compd., pyrazine deriv., water and isopropanol at 180°C for 96 h; elem. anal.;	42.6%

[2,2]bipyridinyl (366-18-7) + pyrazine-2,6-dicarboxylic acid (940-07-8) + water (7732-18-5) + cobalt(II) diacetate tetrahydrate (6147-53-1) → [Co(pyrazine-2,6-dicarboxylic acid(-2H))(2,2'-bipyridine)(H2O)]*0.5H2O

Conditions	Yield
In water; isopropyl alcohol High Pressure; equimolar organic ligands and Co-compound put into water and iPrOH; sealed into autoclave; heated at 140°C for 4 days; cooled slowly to room temp.; filtered; allowed to stand for 4 weeks at room temp.; elem. anal.;	39%

methanol (67-56-1) + 1,2-bis(4'-pyridyl)ethane (4916-57-8) + pyrazine-2,6-dicarboxylic acid (940-07-8) + water (7732-18-5) + cobalt(II) diacetate tetrahydrate (6147-53-1) → [Co2(pyrazine-2,6-dicarboxylic acid(-2H))2(1,2-bis(4-pyridyl)ethane)(H2O)4]*0.5CH3OH*H2O

Conditions	Yield
With NaOH In methanol; water High Pressure; equimolar organic ligands, NaOH and Co-compound put into water and MeOH;sealed into autoclave; heated at 100°C for 4 days; cooled slowly to room temp.; filtered; allowed to stand for 2 months at room temp.; elem. anal.;	37%

1,2-bis(4'-pyridyl)ethane (4916-57-8) + pyrazine-2,6-dicarboxylic acid (940-07-8) + water (7732-18-5) + cobalt(II) diacetate tetrahydrate (6147-53-1) → [Co(pyrazine-2,6-dicarboxylic acid(-2H))(1,2-bis(4-pyridyl)ethane)]*0.125(1,2-bis(4-pyridyl)ethane)*1.75H2O

Conditions	Yield
With NaOH In water High Pressure; equimolar organic ligands, aq. NaOH and Co-compound put into water; sealed into autoclave; heated at 100°C for 4 days; cooled slowly to room temp.; filtered; allowed to stand for 2 months at room temp.; elem. anal.;	31%

pyrazine-2,6-dicarboxylic acid (940-07-8) + hexakis(urea)titanium(III) perchlorate → Ti(3+)*C4H2N2(CO2)2(2-)*C4H2N2(CO2)(CO2H)(1-)*6H2O = H{Ti(C4H2N2(COO)2)2}*6H2O

Conditions	Yield
In water addn. of the Ti complex to a soln. of the dicarboxylic acid in water under Ar; filtn., ppt. is washed, dried, elem. anal.;	30%

copper(ll) sulfate pentahydrate + pyrazine-2,6-dicarboxylic acid (940-07-8) + water (7732-18-5) + 4,4'-bipyridine dihydrate (1185291-78-4) → [Cu(pyrazine-2,6-dicarboxylic acid-2H)(4,4'-bipyridine)]*H2O (937021-45-9)

Conditions	Yield
With NaOH In water High Pressure; mixt. of CuSO4*5H2O (0.15 mmol), pyrazine-2,6-dicarboxylic acid (0.1 mmol), 4,4'-bipyridine hydrate (0.15 mmol), H2O (8 ml) and 0.65 M NaOH (0.3ml) sealed in Teflon-lined stainless steel reactor (23 ml); heated (140 °C, 96 h); cooled (10°C/3 h) to 100°C and then to room temp.; crystals washed with deionized H2O; dried in air; elem. anal.;	27%

pyrazine-2,6-dicarboxylic acid (940-07-8) + manganese(II) carbonate monohydrate (128545-04-0) + water (7732-18-5) → [Mn(pyrazine-2,6-dicarboxylic acid(-2H))(H2O)1.5]

Conditions	Yield
With Yb(NO3)3*6H2O; NaOH In water High Pressure; organic ligands, Yb-compound, a drop of NaOH and Mn-compound put into water; sealed into autoclave; heated at 160°C for 96 h; cooled slowly to room temp.; washed with deionized water; dried in air; elem. anal.;	26%

iron(III) chloride hexahydrate + pyrazine-2,6-dicarboxylic acid (940-07-8) → H{Fe(pyrazine-2,6-dicarboxylate)2}*4H2O + {Fe2(pyrazine-2,6-dicarboxylate)3}*8H2O

Conditions	Yield
In water 20°C; filtn. of the Fe2-complex, filtrate is warmed to 50°C, cooled to 2°C, filtn., ppt. is washed, dried, elem. anal.;	A 21% B n/a

pyrazine-2,6-dicarboxylic acid (940-07-8) → piperazine-2,6-dicarboxylic acid (89601-11-6)

Conditions	Yield
With potassium hydroxide; palladium on activated charcoal at 50℃; Hydrogenation;

Upstream product

• 23611-75-8 6-chloro-pyrazine-2-carboxylic acid methyl ester 
• 70911-23-8 pyrazine-2,6-dicarbonitrile 
• 35042-26-3 dimethyl pyrazine-2,6-dicarboxylate 
• 23046-95-9 2,3,5-pyrazine-tricarboxylic acid 

Downstream Products

• 89601-11-6 Piperazin-2,6-dicarbonsaeure 
• 85246-65-7 bis(triphenylphosphine)(2,6-pyrazinedicarboxylato)copper(I) 

Relevant articles and documents

Pyrazine-functionalized calix[4]arenes: Synthesis by palladium-catalyzed cross-coupling with phosphorus pronucleophiles and metal ion extraction properties

A series of pyrazine-based calix[4]arene extractants was prepared by a stepwise functionalization, comprising palladium-catalyzed exhaustive cross-coupling of di- and tetrasubstituted calix[4]arenes bearing chloropyrazine moieties. The extraction behavior of the synthesized ligands was studied on Am-Eu mixtures under acidic feed conditions similar to those prevailing in nuclear wastes. Phosphorylpyrazine-bearing extractants exhibited a very high acid resistivity and a high affinity for americium giving D values as high as 794 at pH 1. The synergistic effect of the chlorinated cobalt bis(dicarbollide) anion [(B9C2H8Cl3) 2Co]- (CCD-anion), as well as the effect of the calix[4]arene platform compared to monovalent ligands, was investigated. The presence of 1 mM CCD resulted in a 105 times increase in the D value.