| Identification | More | [Name]
4,5-Difluoro-2-nitrobenzoic acid | [CAS]
20372-63-8 | [Synonyms]
2-NITRO-4,5-DIFLUOROBENZOIC ACID
4,5-DIFLUORO-2-NITROBENZOIC ACID | [EINECS(EC#)]
1533716-785-6 | [Molecular Formula]
C7H3F2NO4 | [MDL Number]
MFCD00799521 | [Molecular Weight]
203.1 | [MOL File]
20372-63-8.mol |
| Safety Data | Back Directory | [Hazard Codes ]
Xi | [Risk Statements ]
R36/37/38:Irritating to eyes, respiratory system and skin . | [Safety Statements ]
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice . | [WGK Germany ]
3
| [Hazard Note ]
Irritant | [HazardClass ]
IRRITANT | [HS Code ]
29163990 |
| Hazard Information | Back Directory | [Chemical Properties]
Solid | [General Description]
4,5-Difluoro-2-nitrobenzoic acid can be obtained from the nitration of 4,5-difluorobenzoic acid or 3,4-difluorobenzoic acid. | [Synthesis]
Step 1: 3,4-difluorobenzoic acid (120.0 g, 0.7589 mol) and concentrated sulfuric acid (96.4%, 1.0 L) were added to a 2 L three-necked round-bottom flask. The mixture was mechanically stirred at room temperature for 1.0 hour and then cooled to 0°C. Fuming nitric acid (>90% HNO3 content, 57.30 mL, 1.273 mmol, 1.677 eq.) was added dropwise over 30 minutes. After addition, the reaction mixture was stirred at room temperature for 16 hours. Subsequently, the reaction mixture was slowly poured into crushed ice (5 Kg) under stirring. 4,5-difluoro-2-nitrobenzoic acid precipitated as a yellow solid. The slurry was continued to be stirred at 0 °C for 0.5 h. The solid product was then collected by filtration through a Brinell funnel. The yellowish solid was washed with cold water and air dried; 120 g of product was obtained in 79% yield. | [References]
[1] Journal of Heterocyclic Chemistry, 2001, vol. 38, # 1, p. 61 - 67
[2] Farmaco, 2001, vol. 56, # 9, p. 664 - 676
[3] Patent: WO2008/36843, 2008, A2. Location in patent: Page/Page column 31-33
[4] Patent: US4994606, 1991, A
[5] Patent: US5003103, 1991, A |
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