2,4-ジニトロフルオロベンゼン

1.482 at 68 °F (NTP, 1992) - Denser than water; will sink

Density: 1.4718 g/cu cm at 54 °C

0.1 to 1.0 mg/mL at 67.5 °F (NTP, 1992)

Soluble in benzene, ether, propylene glycol

Soluble in ethanol; slightly soluble in chloroform

In water, 400 mg/L at 25 °C

greater than 235 °F (NTP, 1992)

Flash point > 113 °C

565 °F at 760 mmHg ; 352 °F at 25 mmHg ; 271 °F at 2 mmHg (NTP, 1992)

296 °C

81.5 to 86.0 °F (NTP, 1992)

25.8 °C

2,4-dinitrofluorobenzene appears as clear yellow crystals or yellow crystalline solid. (NTP, 1992)

Pale yellow solid; [Merck Index] Yellow low melting crystalline solid; mp = 23-26 deg C; [MSDSonline]

Danger

H301 (12%): Toxic if swallowed [Danger Acute toxicity, oral]

P260, P261, P262, P264, P264+P265, P270, P271, P272, P280, P284, P301+P316, P301+P317, P302+P352, P304+P340, P305+P351+P338, P305+P354+P338, P316, P317, P319, P320, P321, P330, P332+P317, P333+P317, P337+P317, P361+P364, P362+P364, P403+P233, P405, and P501 (click each P-code to see the statement)

Aggregated GHS information provided per 50 reports by companies from 10 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.

Warning

H315: Causes skin irritation [Warning Skin corrosion/irritation]

Chemical: Benzene, 1-fluoro-2,4-dinitro-

1-Fluoro-2,4-dinitrobenzene: Does not have an individual approval but may be used under an appropriate group standard

A mutagen and sensitizer; [RTECS] Emergency treatment: Methemoglobinemia; [HSDB] A strong irritant and vesicant; [HSDB] A skin, eye, and mucous membrane irritant; This chemical is highly toxic, a powerful irritant, and causes blistering. It caused allergic reactions and dermatitis by skin contact or inhalation. It can be absorbed through the skin. [CAMEO] A powerful irritant and vesicant; May be absorbed through skin; May cause skin and respiratory sensitization after prolonged contact; [MSDSonline]

REVIEW WITH 19 REFERENCES. DNFB IS WIDELY USED IN BIOCHEM RESEARCH & TEACHING FOR CHARACTERIZATION OF AMINES, ESP AMINO ACIDS, & FOR EXPTL IMMUNIZATION. EXPTL OBSERVATIONS & CLINICAL REPORTS ARE REVIEWED & FACTORS INFLUENCING (HUMAN) SENSITIZATION ARE DISCUSSED. RECOMMENDATIONS ARE GIVEN FOR PROPER USE OF PROTECTIVE GLOVES & AVOIDANCE OF SPRAY INHALATION.[THOMPSON JS; EDMONDS OP; SAFETY ASPECTS OF HANDLING THE POTENT ALLERGEN 1-FLUORO-2,4-DINITROBENZENE; ANN OCCUP HYG 23(1) 27 (1980)]

Reacts with oxidizing agents (NTP, 1992). When air was admitted after vacuum evaporation of an ether peroxide solution, a violent explosion occurred. A halogenated aromatic nitro compound. Aromatic nitro compounds range from slight to strong oxidizing agents. If mixed with reducing agents, including hydrides, sulfides and nitrides, they may begin a vigorous reaction that culminates in a detonation. The aromatic nitro compounds may explode in the presence of a base such as sodium hydroxide or potassium hydroxide even in the presence of water or organic solvents. The explosive tendencies of aromatic nitro compounds are increased by the presence of multiple nitro groups.

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Health: Highly toxic, may be fatal if inhaled, swallowed or absorbed through skin. Contact with molten substance may cause severe burns to skin and eyes. Avoid any skin contact. Effects of contact or inhalation may be delayed. Fire may produce irritating, corrosive and/or toxic gases. Runoff from fire control or dilution water may be corrosive and/or toxic and cause pollution. /Dinitrobenzenes; Dinitrobenzenes, liquid; Dinitrobenzenes, solid/

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Fire or Explosion: Combustible material: may burn but does not ignite readily. Containers may explode when heated. Runoff may pollute waterways. Substance may be transported in a molten form. /Dinitrobenzenes; Dinitrobenzenes, liquid; Dinitrobenzenes, solid/

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Public Safety: CALL Emergency Response Telephone Number ... As an immediate precautionary measure, isolate spill or leak area in all directions for at least 50 meters (150 feet) for liquids and at least 25 meters (75 feet) for solids. Keep unauthorized personnel away. Stay upwind. Keep out of low areas. /Dinitrobenzenes; Dinitrobenzenes, liquid; Dinitrobenzenes, solid/

/GUIDE 152: SUBSTANCES - TOXIC (COMBUSTIBLE)/ Protective Clothing: Wear positive pressure self-contained breathing apparatus (SCBA). Wear chemical protective clothing that is specifically recommended by the manufacturer. It may provide little or no thermal protection. Structural firefighters' protective clothing provides limited protection in fire situations ONLY; it is not effective in spill situations where direct contact with the substance is possible. /Dinitrobenzenes; Dinitrobenzenes, liquid; Dinitrobenzenes, solid/

For more DOT Emergency Guidelines (Complete) data for 1-FLUORO-2,4-DINITROBENZENE (8 total), please visit the HSDB record page.

Acute Tox. 3 (12%)

Skin corrosion/irritation - Category 2

No person may /transport,/ offer or accept a hazardous material for transportation in commerce unless that person is registered in conformance ... and the hazardous material is properly classed, described, packaged, marked, labeled, and in condition for shipment as required or authorized by ... /the hazardous materials regulations (49 CFR 171-177)./

The International Air Transport Association (IATA) Dangerous Goods Regulations are published by the IATA Dangerous Goods Board pursuant to IATA Resolutions 618 and 619 and constitute a manual of industry carrier regulations to be followed by all IATA Member airlines when transporting hazardous materials.

The International Maritime Dangerous Goods Code lays down basic principles for transporting hazardous chemicals. Detailed recommendations for individual substances and a number of recommendations for good practice are included in the classes dealing with such substances. A general index of technical names has also been compiled. This index should always be consulted when attempting to locate the appropriate procedures to be used when shipping any substance or article.

EYES: First check the victim for contact lenses and remove if present. Flush victim's eyes with water or normal saline solution for 20 to 30 minutes while simultaneously calling a hospital or poison control center. Do not put any ointments, oils, or medication in the victim's eyes without specific instructions from a physician. IMMEDIATELY transport the victim after flushing eyes to a hospital even if no symptoms (such as redness or irritation) develop.

SMALL SPILLS AND LEAKAGE: Should a spill occur while you are handling this chemical, you should dampen the solid spill material with alcohol, then transfer the dampened material to a suitable container. Use absorbent paper dampened with alcohol to pick up any remaining material. Seal the absorbent paper, and any of your clothes, which may be contaminated, in a vapor-tight plastic bag for eventual disposal. Solvent wash all contaminated surfaces with alcohol followed by washing with a strong soap and water solution. Do not reenter the contaminate area until the Safety Officer (or other responsible person) has verified that the area has been properly cleaned.

SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational harm/injury/toxicity or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air quality; potential migration in soil or water; effects on animal and plant life; and conformance with environmental and public health regulations.

UV-IRRADIATION OF SKIN OR TOPICAL APPLICATION OF CORTICOSTEROIDS CAN CREATE LOCAL MILIEU IN WHICH 2,4-DININTRO-1-FLUOROBENZENE CANNOT FUNCTION AS EFFECTIVE STIMULATOR OF CONTACT HYPERSENSITIVITY.

ANTIGENIC COMPETITION (DEPRESSED CONTACT SENSITIVITY TO PICRYL CHLORIDE) WAS INDUCED IN MICE BY PAINTING WITH DNFB (600 MUG) & BY IV, IP & ORAL ADMIN (600 MUG). ANTIGENIC COMPETITION ABOLISHED BY CYCLOPHOSPHAMIDE (5 MG, IP) GIVEN 4 DAYS AFTER IV DNFB (0 TO 600 MUG) OR 4-ETHOXYMETHYLENE 2-PHENYLOXAZOLONE (0 TO 600 MUG), & BY THYMECTOMY 6 WK PRIOR TO INJECTION OF DNFB. THYMUS-DERIVED SUPPRESSOR CELLS MAY BE INVOLVED IN ANTIGENIC COMPETITION INDUCED BY IV DNFB. IV DNFB DID NOT INDUCE CONTACT SENSITIVITY IN NORMAL MICE, AS IT DID IN MICE PRETREATED WITH CYCLOPHOSPHAMIDE 2 DAYS PRIOR TO INJECTION.

SUPPRESSOR T CELLS ACTING ON EFFERENT PHASE (TS-EFF) OF DINITROFLUOROBENZENE-CONTACT SENSITIVITY WERE INDUCED-IN BALB/C MICE BY INJECTION OF DINITROBENZENESULFONATE (DNBSO3) & SUBSEQUENT PAINTING (SENSITIZATION) WITH DNFB. TS-EFF CELLS RELEASED SUPPRESSOR FACTOR, ANTIGEN & STRAIN SPECIFIC, WHICH WAS ACTIVE IN VIVO IN SENSITIZED RECIPIENTS. ADMIN OF DNBSO3 ALONE GENERATED SUPPRESSOR T CELLS, WHICH ACTED ONLY ON AFFERENT PHASE (TS-EFF). SUPPRESSOR T CELLS COULD NOT BE DETECTED IN MICE PAINTED WITH DNFB & DESENSITIZED LATER BY INJECTION OF DNBSO3.

ANTIBODY MEDIATED & CELL MEDIATED IMMUNE FUNCTIONS OF OFFSPRING FROM NEW ZEALAND WHITE RABBITS FED CONTROL CHOW OR CHOW CONTAINING 10, 100 OR 250 PPM OF AROCLOR 1248 (PCB) WERE ASSESSED. ONLY OFFSPRING FROM MOTHERS FED 250 PPM HAD SIGNIFICANTLY LOWER CONTACT SENSITIVITY RESPONSE TO DNFB. THERE WAS NO DECR IN PLAQUE FORMING CELL RESPONSE TO SHEEP RED BLOOD CELLS (SRBC) OR SERUM ANTI-SRBC ANTIBODY TITERS AT ANY EXPOSURE LEVEL. SPLEEN & THYMUS DID NOT REVEAL ANY CHANGES IN CELLULARITY ASSOC WITH IMMUNOSUPPRESSION; NOR DID PERIPHERAL BLOOD LYMPHOCYTES DIFFER FROM CONTROLS.

For more Interactions (Complete) data for 1-FLUORO-2,4-DINITROBENZENE (6 total), please visit the HSDB record page.

TERRESTRIAL FATE: Based on a classification scheme(1), an estimated Koc value of 575(SRC), determined from a structure estimation method(2), indicates that 1-fluoro-2,4-dinitrobenzene is expected to have low mobility in soil(SRC). It has been shown that nitrobenzenes adsorb strongly to clay surfaces and the mobility of 1-fluoro-2,4-dinitrobenzene is expected to be low in soils rich in clay content(3,4). Volatilization of 1-fluoro-2,4-dinitrobenzene from moist soil surfaces is not expected to be an important fate process(SRC) given an estimated Henry's Law constant of 9.8X10-8 atm-cu m/mole(SRC), using a fragment constant estimation method(2). 1-Fluoro-2,4-dinitrobenzene is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.4X10-3 mm Hg(SRC), determined from a fragment constant method(2). The half-life of 1-fluoro-2,4-dinitrobenzene in a dry silt loam soil was greater than 50 days(4) suggesting biodegradation occurs slowly in soil(SRC).

AQUATIC FATE: Based on a classification scheme(1), an estimated Koc value of 575(SRC), determined from a structure estimation method(2), indicates that 1-fluoro-2,4-dinitrobenzene is expected to adsorb to suspended solids and sediment(SRC). Volatilization from water surfaces is not expected(3) based upon an estimated Henry's Law constant of 9.8X10-8 atm-cu m/mole(SRC), developed using a fragment constant estimation method(2). According to a classification scheme(4), an estimated BCF of 7(SRC), from an estimated log Kow of 1.83(2) and a regression-derived equation(2), suggests the potential for bioconcentration in aquatic organisms is low(SRC). Hydrolysis is not expected to be an important fate process for 1-fluoro-2,4-dinitrobenzene since this compound lacks functional groups that undergo hydrolysis under environmental conditions(3). The half-life of 1-fluoro-2,4-dinitrobenzene in a dry silt loam soil was greater than 50 days(7) suggesting biodegradation occurs slowly in water(SRC).

ATMOSPHERIC FATE: According to a model of gas/particle partitioning of semivolatile organic compounds in the atmosphere(1), 1-fluoro-2,4-dinitrobenzene, which has an estimated vapor pressure of 2.4X10-3 mm Hg at 25 °C(SRC), determined from a fragment constant method(2), is expected to exist solely as a vapor in the ambient atmosphere. Vapor-phase 1-fluoro-2,4-dinitrobenzene is degraded in the atmosphere by reaction with photochemically-produced hydroxyl radicals(SRC); the half-life for this reaction in air is estimated to be 420 days(SRC), calculated from its rate constant of 3.8X10-14 cu cm/molecule-sec at 25 °C(SRC) determined using a structure estimation method(2). 1-Fluoro-2,4-dinitrobenzene absorbs light greater than 290 nm(3) and may be susceptible to direct photolysis in sunlight(SRC).

The following link will take the user to the National Toxicology Program (NTP) Test Agent Search Results page, which tabulates all of the "Standard Toxicology & Carcinogenesis Studies", "Developmental Studies", and "Genetic Toxicity Studies" performed with this chemical. Clicking on the "Testing Status" link will take the user to the status (i.e., in review, in progress, in preparation, on test, completed, etc.) and results of all the studies that the NTP has done on this chemical.[Available from: http://ntp-apps.niehs.nih.gov/ntp_tox/index.cfm?fuseaction=ntpsearch.searchresults&searchterm=70-34-8]

Using a structure estimation method based on molecular connectivity indices(1), the Koc for 1-fluoro-2,4-dinitrobenzene can be estimated to be 575(SRC). According to a classification scheme(2), this estimated Koc value suggests that 1-fluoro-2,4-dinitrobenzene is expected to have low mobility in soil. It has been shown that nitrobenzenes adsorb strongly to clay surfaces and the mobility of 1-fluoro-2,4-dinitrobenzene is expected to be low in soils rich in clay content(3,4).

An estimated BCF of 7 was calculated in fish for 1-fluoro-2,4-dinitrobenzene(SRC), using an estimated log Kow of 1.83(1) and a regression-derived equation(1). According to a classification scheme(2), this BCF suggests the potential for bioconcentration in aquatic organisms is low.

The Henry's Law constant for 1-fluoro-2,4-dinitrobenzene is estimated as 9.8X10-8 atm-cu m/mole(SRC) using a fragment constant estimation method(1). This Henry's Law constant indicates that 1-fluoro-2,4-dinitrobenzene is expected to be essentially nonvolatile from water surfaces(2). 1-Fluoro-2,4-dinitrobenzene's estimated Henry's Law constant(1) indicates that volatilization from moist soil surfaces is not expected to be an important environmental fate process(SRC). 1-Fluoro-2,4-dinitrobenzene is not expected to volatilize from dry soil surfaces(SRC) based upon an estimated vapor pressure of 2.4X10-3 mm Hg(SRC), determined from a fragment constant method(1).

/LABORATORY ANIMALS: Acute Exposure/ ...TESTED IN RABBITS & RATS AT NEAR-LETHAL DOSES FOR TOXIC EFFECTS ON FUNDUS OF EYE, BUT NONE...DETECTED OPHTHALMOSCOPICALLY OR HISTOLOGICALLY. SURVIVING RABBIT RETINA IS DAMAGED IN VITRO AT CONCN OF 0.05 MOLAR.

/LABORATORY ANIMALS: Chronic Exposure or Carcinogenicity/ SEVERAL GROUPS OF MICE (STRAINS SWISS, BALB/C OR C57BL/6) WERE ADMIN 1 TOPICAL DOSE OF 7,12-DIMETHYLBENZANTHRACENE (DMBA, 125 UG). IN MICE ADMIN 5 TOPICAL DOSES/WK OF 0.1% 1-FLUORO-2,4-DINITROBENZENE (DNFB) IN ACETONE SOLN, SKIN TUMORS DEVELOPED IN ONLY 4 WK IN SOME CASES; AFTER 38 WK, THE TUMOR INCIDENCE WAS 70% (21/30 SWISS MICE). LOWER CONCN (0.03%) OF DNFB INDUCED TUMORS IN 38% OF 21 EVALUABLE DMBA-TREATED SWISS MICE. THE C57BL/6 MICE DEVELOPED FEWER TUMORS THAN THE SWISS OR BALB/C MICE AFTER TREATMENT WITH DMBA FOLLOWED BY EITHER DNFB OR CROTON OIL.

/GENOTOXICITY/ Dose-dependent mutagenicity demonstrated in ames test with samonella & was toxic at very high concn (100 nL/plate). Although, S9 metabolic activation fraction from rat liver blocked mutagenic activity of low concn & diminished toxicity, it did not affect mutagenicity at intermediate to high concn (approx 10-50 nL/plate).

/GENOTOXICITY/ /SRP: GENOTOXIC/ POTENTIAL UTILIZING VARIOUS METHODS AVAIL IN V-79 CHINESE HAMSTER CELLS WAS INVESTIGATED. EXPOSURE DID NOT RESULT IN ANY UNSCHEDULED DNA SYNTH, NOR DID IT INCR FREQUENCY OF SISTER CHROMATID EXCHANGES IN V-79 CELLS IN PRESENCE OR ABSENCE OF RAT LIVER POSTMITOCHONDRIAL SUPERNATANT (S-15). FORWARD MUTATIONS, EITHER TO OUABAIN OR 6-THIOGUANINE RESISTANCE, WERE NOT INDUCED IN PRESENCE OR ABSENCE OF S-15. IT WAS ABLE TO INDUCE REVERSIONS IN METHIONINE-REQUIRING ESCHERICHIA COLI AUXOTROPHS IN DOSE-DEPENDENT FASHION & IT INHIBITED METABOLIC COOPERATION, IN DOSE-DEPENDENT MANNER, IN V-79 CELLS. ...

For more Non-Human Toxicity Excerpts (Complete) data for 1-FLUORO-2,4-DINITROBENZENE (6 total), please visit the HSDB record page.

The rate constant for the vapor-phase reaction of 1-fluoro-2,4-dinitrobenzene with photochemically-produced hydroxyl radicals has been estimated as 3.8X10-14 cu cm/molecule-sec at 25 °C(SRC) using a structure estimation method(1). This corresponds to an atmospheric half-life of about 420 days at an atmospheric concentration of 5X10+5 hydroxyl radicals per cu cm(1). 1-Fluoro-2,4-dinitrobenzene absorbs light greater than 290 nm and may be susceptible to direct photolysis in sunlight(SRC). Hydrolysis is not expected to be an important fate process for 1-fluoro-2,4-dinitrobenzene since this compound lacks functional groups that undergo hydrolysis under environmental conditions(3).

NIOSH (NOES Survey 1981-1983) has statistically estimated that 28 workers (0 of these were female) were potentially exposed to 1-fluoro-2,4-dinitrobenzene in the US(1). Occupational exposure to 1-fluoro-2,4-dinitrobenzene may occur through dermal contact with this compound at workplaces where 1-fluoro-2,4-dinitrobenzene is produced or used(SRC).

Contact sensitivity to 2,4 dinitrofluorobenzene is maximal six days after sensitization but declines rapidly, due to autoanti-idiotypic antibodies produced by the host. The studies presented here indicate that this down regulation by anti-Id is a C independent active process involving a subset of Ia+ T cells in the immune lymph node cell population. Depleting immune LN cells of Ia+ T cells renders them insensitive to inhibition by anti-Id alone, although the same population is inhibited by treatment anti-Id plus C. This c(M population is rendered sensitive to inhibition by anti-Id alone by adding untreated DNFB sensitized LN cells but not by adding normal LN cells. Further studies showed that suppression by anti-Id activated Ia+ T cells occurs locally at the skin test site and is antigen nonspecific. These data indicate the natural regulation of CS to DNFB by autoanti-Id antibodies involves a negative feedback regulatory loop.

Chemokines are involved in the control of dendritic cell (DC) trafficking, which is critical for the immune response, namely in allergic contact dermatitis (ACD). In this work, we investigated by flow cytometry the effect of the contact sensitizers 2,4-dinitrofluorobenzene (DNFB), 1,4-phenylenediamine (PPD) and nickel sulfate (NiSO(4)), on the surface expression of the chemokine receptors CCR6 and CXCR4 in DC. As an experimental model of a DC we used a fetal skin-derived dendritic cell line (FSDC), which has morphological, phenotypical and functional characteristics of skin DC. Our results show that all the skin sensitizers studied decreased the membrane expression of the chemokine receptors CCR6 and CXCR4. In contrast, 2,4-dichloronitrobenzene (DCNB), the inactive analogue of DNFB without contact sensitizing properties, was without effect on the surface expression of these receptors. Lipopolysaccharide (LPS), which induces the maturation of DC, also reduced surface CCR6 and CXCR4 expression.

Early changes in gene expression have been identified by cDNA microarray technology. Analysis of draining auricular lymph node tissue sampled at 48 h following exposure to the potent contact allergen 2,4-dinitrofluorobenzene (DNFB) provided examples of up- and down-regulated genes, including onzin and guanylate binding protein 2, and glycosylation-dependent cell adhesion molecule 1 (GlyCAM-1), respectively. Allergen-induced changes in these three genes were confirmed in dose-response and kinetic analyses using Northern blotting and/or reverse transcription-polymerase chain reaction techniques. The results confirmed that these genes are robust and relatively sensitive markers of early changes provoked in the lymph node by contact allergen. Upon further investigation, it was found that altered expression of the adhesion molecule GlyCAM-1 was not restricted to treatment with DNFB. Topical sensitization of mice to a chemically unrelated contact allergen, oxazolone, was also associated with a decrease in the expression of mRNA for GlyCAM-1. Supplementary experiments revealed that changes in expression of this gene are independent of the stimulation by chemical allergens of proliferative responses by draining lymph node cells. Taken together these data indicate that the expression of GlyCAM-1 is down-regulated rapidly following epicutaneous treatment of mice with chemical allergens, but that this reduction is associated primarily with changes in lymph node cell number, or some other aspect of lymph node activation, rather than proliferation.

The skin sensitizer 2,4-dinitrofluorobenzene (DNFB) provokes delayed hypersensitivity responses as a result of topical application to the skin. Here, we demonstrate that DNFB modifies proteins in RAW 264.7 cells and skin tissues in NC/Nga mice; we also show the functional involvement of DNFB-induced modification of cellular proteins in the DNFB-induced macrophage inflammatory protein (MIP)-2 gene expression in RAW 264.7 cells. In addition, we demonstrate that DNFB strongly induces reactive oxygen species (ROS) production. Our RT-PCR analysis and reporter gene assays reveal that the DNFB-induced intracellular ROS production is necessary for MIP-2 gene expression by DNFB. We observed that the vitamin C and chemical oxidant scavenger N-acetyl-cysteine have an inhibitory effect on the generation of ROS, the activation of MAP kinase pathways, and the MIP-2 gene expression in DNFB-treated RAW 264.7 cells. These results provide insight into the mechanisms involved in DNFB-induced contact hypersensitivity.

Used as a reagent (labeling terminal amino acid groups and modified Wohl degradations of aldoses) and hapten; [Merck Index]

Reagent for labeling a terminal amino acid group; in modified Wohl degradations of aldoses. As hapten.

Alkylating agent, reagent in elucidating amino acid sequence in proteins

In commercial batch or semicontinuous operations, /such as/ the Halex process, potassium fluoride and the activated chloroaromatic compound are thoroughly mixed (1:1) with a large volume of an aprotic solvent (dimethyl sulfoxide or sulfolane) and are heated to 150-250 °C. The reaction is 90% complete within 48 hr. Removal of KCl and distillation of the product present no difficulty ... The following commercially important ... /intermediate is/ obtained by the Halex process: ... 1- fluoro-2,4-dinitrobenzene from 1- chloro-2,4-dinitrobenzene.