Name | Citrazinic acid |
Synonyms | CITRAZANICACID Citrazinic acid CITRAZINIC ACID CRYSTALLINE 2,6-Dihydroxyisonicotinic acid CITRAZINIC ACID PHOTOGRAPHIC GRADE 2,6-Dihydroxy-4-pyridincarbonsaeure 2,6-Dihydroxypyridine-4-carboxylic acid 3,5-dihydroxypyridine-4-carboxylic acid 2,6-Dihydroxy-4-pyridinecarboxylic acid 1,2-dihydro-6-hydroxy-2-oxo-isonicotinicaci 6-hydroxy-2-oxo-1,2-dihydropyridine-4-carboxylate 1,2-dihydro-6-hydroxy-2-oxo-4-pyridinecarboxylicaci 1,2-Dihydro-6-hydroxy-2-oxo-4-pyridinecarboxylicacid 6-hydroxy-2-oxo-1,2-dihydropyridine-4-carboxylic acid |
CAS | 99-11-6 |
EINECS | 202-731-2 |
InChI | InChI=1/C6H5NO4/c8-4-1-3(6(10)11)2-5(9)7-4/h1-2H,(H,10,11)(H2,7,8,9)/p-1 |
InChIKey | CSGQJHQYWJLPKY-UHFFFAOYSA-N |
Molecular Formula | C6H5NO4 |
Molar Mass | 155.11 |
Density | 0.65 g/cm3 |
Melting Point | >300°C(lit.) |
Boling Point | 278.88°C (rough estimate) |
Flash Point | 180.9°C |
Water Solubility | practically insoluble |
Solubility | Insoluble in water, soluble in alkaline hydroxide and carbonate solution, slightly soluble in hot hydrochloric acid |
Vapor Presure | 3.56E-07mmHg at 25°C |
Appearance | Bright yellow needle crystal |
Color | Yellow |
Merck | 14,2325 |
BRN | 383736 |
pKa | 2.54±0.20(Predicted) |
PH | 3.1-3.5 (100g/l, H2O)(slurry) |
Storage Condition | Inert atmosphere,2-8°C |
Refractive Index | 1.5423 (estimate) |
MDL | MFCD00006274 |
Physical and Chemical Properties | Light yellow needle-like crystal or powder, carbonization above 300 ℃ but not melting. Soluble in sodium hydroxide or sodium carbonate solution, placed into blue, slightly soluble in hydrochloride, almost insoluble in cold water. The color is gradually darkened in light or open air. |
Use | Used as pharmaceutical, pesticide intermediates |
Hazard Symbols | Xi - Irritant![]() |
Risk Codes | 36/37/38 - Irritating to eyes, respiratory system and skin. |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36 - Wear suitable protective clothing. S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S22 - Do not breathe dust. |
WGK Germany | 1 |
RTECS | NS1400000 |
TSCA | Yes |
HS Code | 29333999 |
NIST chemical information | information provided by: webbook.nist.gov (external link) |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Use | for the synthesis of pharmaceuticals, dyes and color couplers for color films. used as pharmaceutical and pesticide intermediates |
production method | from citric acid by esterification, ammonolysis, ring closure. The esterification reaction was carried out in the presence of sulfuric acid. After 48h of dehydration, the solvent and ethanol were recovered, and the residue was washed with water, alkali wash and water wash to pH 6 to obtain crude triethyl citrate. Ammonia was added and ammonia was flushed to saturation. After standing, ammonia is saturated again, once a day, a total of three times, and the crystals are filtered out. The obtained citric acid triformate is kept in the presence of sulfuric acid at about 120 ℃ for 3H, and slowly poured into distilled water, the crude product is obtained, and then refined by acid-base to obtain limonazinic acid. The preparation method using trimethyl citrate is approximately the same as described above. Aqueous ammonia was added to trimethyl citrate, and the mixture was placed at room temperature for about 48H. After concentration, 75% sulfuric acid was added, placed for 12h, heated at 130 ° C. For 10min, diluted with water, and the precipitate was filtered to obtain a crude product. The crude product is dissolved in ammonia water, and the precipitate is obtained by adding hydrochloric acid, filtering, washing with water and drying. The yield was 69%. |