Citrazinic acid

Names
Preferred IUPAC name

6-Hydroxy-2-oxo-1,2-dihydropyridine-4-carboxylic acid

Other names

2,6-Dihydroxyisonicotinic acid; 2,6-Dihydroxypyridine-4-carboxylic acid

Identifiers

CAS Number

* 99-11-6 Y

3D model (JSmol)

* Interactive image

ChEBI |

* CHEBI:CHEBI:184700

ChemSpider |

* 7147 N

ECHA InfoCard | 100.002.483
EC Number |

* 202-731-2

MeSH | acid Citrazinic acid

PubChem CID

* 7425

RTECS number |

* NS1400000

UNII |

* N8Q4XFV86A Y

CompTox Dashboard (EPA)

* DTXSID3059185

InChI

* InChI=1S/C6H5NO4/c8-4-1-3(6(10)11)2-5(9)7-4/h1-2H,(H,10,11)(H2,7,8,9) N

Key: CSGQJHQYWJLPKY-UHFFFAOYSA-N N

SMILES

* O=C(O)C=1\C=C(\O)NC(=O)C=1

Properties

Chemical formula

| C6H5NO4
Molar mass | 155.109 g·mol−1
Appearance  | yellow powder
Melting point | >300 °C (decomp.)

Solubility in water

| Slightly soluble
Solubility | Slightly soluble in methanol, DMSO, acidic solutions
Very soluble in alkaline solutions
Hazards
GHS labelling:

Pictograms

Signal word

| Warning

Hazard statements

| H315, H319, H335

Precautionary statements

| P261, P280, P305+P351+P338
NFPA 704 (fire diamond)  |

Lethal dose or concentration (LD, LC):

LD50 (median dose)

| > 3200 mg/kg ( Rat )

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

N verify (what is YN ?)

Infobox references

Chemical compound

Citrazinic acid (CZA) is a heterocyclic compound consisting of a dihydropyridine ring derived with a carboxylate group. The yellow solid exists as multiple tautomers, and it frequently forms dimers.[1]

Citrazinic acid is commonly formed in citric acid based carbon nanodots (CND). It is responsible for the blue light found in citric acid CNDs. The wavelengths of light emitted by citrazinic in CNDs can be shifted by changing the pH of the solution.[2]

## Preparation[edit]

Citrazinic acid can be prepared creating a solution of citric acid and toluenesulfonic acid, which forms a 1,3-diester. That solution, when added to a heated ammonia solution results in citrazinic acid.[3]

## References[edit]

1. ^ Stagi L, Mura S, Malfatti L, Carbonaro CM, Ricci PC, Porcu S, et al. (May 2020). "Anomalous Optical Properties of Citrazinic Acid under Extreme pH Conditions". ACS Omega. 5 (19): 10958–10964. doi:10.1021/acsomega.0c00775. PMC 7241015. PMID 32455216.
2. ^ Mocci F, Olla C, Cappai A, Corpino R, Ricci PC, Chiriu D, et al. (February 2021). "Formation of Citrazinic Acid Ions and Their Contribution to Optical and Magnetic Features of Carbon Nanodots: A Combined Experimental and Computational Approach". Materials. 14 (4): 770. Bibcode:2021Mate...14..770M. doi:10.3390/ma14040770. PMC 7914458. PMID 33562081.
3. ^ Baizer MM, Dub M, Gister S, Steinberg NG (July 1956). "Synthesis of isoniazid from citric acid". Journal of the American Pharmaceutical Association. 45 (7): 478–480. doi:10.1002/jps.3030450714. PMID 13345683.

*[CID]: Compound ID
*[EPA]: U.S. Environmental Protection Agency
*[H315]: H315: Causes skin irritation
*[H319]: H319: Causes serious eye irritation
*[H335]: H335: May cause respiratory irritation
*[P261]: P261: Avoid breathing dust/fume/gas/mist/vapours/spray.
*[P280]: P280: Wear protective gloves/protective clothing/eye protection/face protection.
*[P305+P351+P338]: P305+P351+P338: IF IN EYES: Rinse continuously with water for several minutes. Remove contact lenses if present and easy to do. Continue rinsing.