35674-20-5

Basic information

• Product Name: 3,4-Diiodobenzoic acid
• Synonyms: 3,4-diiodobenzoic acid
• CAS NO: 35674-20-5
• Molecular Formula: C₇H₄I₂O₂
• Molecular Weight: 373.91
• Product Categories: API intermediates
• Mol File: 35674-20-5.mol
• Article Data: 3

Chemical Properties

• Melting Point: 257 °C
• Boiling Point: 380.698 °C at 760 mmHg
• Flash Point: 184.04 °C
• Appearance: /
• Density: 2.559 g/cm³
• Vapor Pressure: 1.78E-06mmHg at 25°C
• Refractive Index: 1.741
• Storage Temp.: 2-8°C
• PKA: 3.67±0.10(Predicted)
• CAS DataBase Reference: 3,4-Diiodobenzoic acid(CAS DataBase Reference)
• NIST Chemistry Reference: 3,4-Diiodobenzoic acid(35674-20-5)
• EPA Substance Registry System: 3,4-Diiodobenzoic acid(35674-20-5)

Safety Data

• Hazardous Substances Data: 35674-20-5(Hazardous Substances Data)

Usage

General Description

3,4-Diiodobenzoic acid is a chemical compound that consists of a benzene ring with carboxylic acid and two iodine substituents. It is a derivative of benzoic acid and is often used as an intermediate in the synthesis of various pharmaceuticals and organic compounds. 3,4-Diiodobenzoic acid has a molecular weight of 397.89 g/mol and a melting point of 212-214°C. It is commonly used in the field of organic chemistry as a building block for the synthesis of more complex compounds due to its reactivity and ability to undergo various chemical reactions, such as esterification, amidation, and halogenation. Additionally, 3,4-Diiodobenzoic acid also has applications in the development of liquid crystals and as a precursor for the production of dyes and pigments.

InChI:InChI=1/C7H4I2O2/c8-5-2-1-4(7(10)11)3-6(5)9/h1-3H,(H,10,11)

Synthetic route

4-amino-3-iodobenzoic acid (2122-63-6) → 3,4-diiodobenzoic acid (35674-20-5)

Conditions	Yield
With sulfuric acid; potassium iodide; sodium nitrite	75%

4-iodobenzoic acid (619-58-9) → 3,4-diiodobenzoic acid (35674-20-5)

Conditions	Yield
With sodium periodate; sulfuric acid; iodine at 25 - 30℃; for 1h;	67%
With sodium iodate; iodine In sulfuric acid at 25 - 30℃; for 1h;	46%

3,4-diiodo-benzaldehyde (477534-94-4) → 3,4-diiodobenzoic acid (35674-20-5)

Conditions	Yield
With permanganate(VII) ion

2-amino-4,5-diiodo-benzoic acid (35674-29-4) → 3,4-diiodobenzoic acid (35674-20-5)

Conditions	Yield
With ethanol; sulfuric acid; sodium nitrite Diazotization;

diazotized 3-iodo-4-amino-benzoic acid → 3,4-diiodobenzoic acid (35674-20-5)

Conditions	Yield
With potassium iodide

4-iodo-2-nitro benzoic acid (116529-62-5) → 3,4-diiodobenzoic acid (35674-20-5)

Conditions	Yield
Multi-step reaction with 3 steps 1: ferrosulfate; ammonia 2: diluted KOH-solution; iodine 3: sulfuric acid; alcohol; sodium nitrite / Diazotization View Scheme

2-amino-4-iodobenzoic acid (20776-54-9) → 3,4-diiodobenzoic acid (35674-20-5)

Conditions	Yield
Multi-step reaction with 2 steps 1: diluted KOH-solution; iodine 2: sulfuric acid; alcohol; sodium nitrite / Diazotization View Scheme

4-iodo-3-nitrobenzaldehyde (101420-88-6) → 3,4-diiodobenzoic acid (35674-20-5)

Conditions	Yield
Multi-step reaction with 2 steps 1: Na2S2O4; water / Diazotieren und Umsetzen mit waessr. Kaliumjodid 2: aqueous permanganate View Scheme

p-(iodophenyl)carboxaldehyde (15164-44-0) → 3,4-diiodobenzoic acid (35674-20-5)

Conditions	Yield
Multi-step reaction with 3 steps 1: concentrated sulfuric acid; sodium nitrate / 15 - 20 °C / anschl. Erhitzen auf 70grad 2: Na2S2O4; water / Diazotieren und Umsetzen mit waessr. Kaliumjodid 3: aqueous permanganate View Scheme

4-amino-benzoic acid (150-13-0) → 3,4-diiodobenzoic acid (35674-20-5)

Conditions	Yield
Multi-step reaction with 2 steps 1: sodium periodate; potassium iodide / water; methanol 2: potassium iodide; sodium nitrite; sulfuric acid View Scheme

triethylene glucol monomethyl ether (112-35-6) + 3,4-diiodobenzoic acid (35674-20-5) → C14H18I2O5 (1071750-65-6)

Conditions	Yield
Stage #1: 3,4-diiodobenzoic acid With dmap; 1-ethyl-(3-(3-dimethylamino)propyl)-carbodiimide hydrochloride In dichloromethane at 0℃; for 1h; Stage #2: triethylene glucol monomethyl ether In dichloromethane at 0 - 20℃;	81%

3,4-diiodobenzoic acid (35674-20-5) → C7H6I2O (1418218-67-3)

Conditions	Yield
With dimethyl sulfide borane In tetrahydrofuran	80%

3,4-diiodobenzoic acid (35674-20-5) → 3,4-diiodo-benzoyl chloride (102014-49-3)

Conditions	Yield
With thionyl chloride

3,4-diiodobenzoic acid (35674-20-5) → C16H20INO3 + C16H20INO3

Conditions	Yield
Multi-step reaction with 6 steps 1: dimethyl sulfide borane / tetrahydrofuran 2: dichloromethane / 0.5 h 3: sodium azide / N,N-dimethyl-formamide / 20 °C 4: triphenylphosphine / water; tetrahydrofuran 5: chloroform / 20 °C 6: tetrakis(triphenylphosphine) palladium(0); triethylamine; copper(l) iodide / 3 h View Scheme

3,4-diiodobenzoic acid (35674-20-5) → C24H31NO5 (1418218-93-5)

Conditions	Yield
Multi-step reaction with 7 steps 1: dimethyl sulfide borane / tetrahydrofuran 2: dichloromethane / 0.5 h 3: sodium azide / N,N-dimethyl-formamide / 20 °C 4: triphenylphosphine / water; tetrahydrofuran 5: chloroform / 20 °C 6: tetrakis(triphenylphosphine) palladium(0); triethylamine; copper(l) iodide / 3 h 7: tetrakis(triphenylphosphine) palladium(0); triethylamine; copper(l) iodide View Scheme

3,4-diiodobenzoic acid (35674-20-5) → C8H8I2O3S (1418218-68-4)

Conditions	Yield
Multi-step reaction with 2 steps 1: dimethyl sulfide borane / tetrahydrofuran 2: dichloromethane / 0.5 h View Scheme

3,4-diiodobenzoic acid (35674-20-5) → C7H5I2N3

Conditions	Yield
Multi-step reaction with 3 steps 1: dimethyl sulfide borane / tetrahydrofuran 2: dichloromethane / 0.5 h 3: sodium azide / N,N-dimethyl-formamide / 20 °C View Scheme

3,4-diiodobenzoic acid (35674-20-5) → 4-aminomethyl-1,2-diiodobenzene

Conditions	Yield
Multi-step reaction with 4 steps 1: dimethyl sulfide borane / tetrahydrofuran 2: dichloromethane / 0.5 h 3: sodium azide / N,N-dimethyl-formamide / 20 °C 4: triphenylphosphine / water; tetrahydrofuran View Scheme

3,4-diiodobenzoic acid (35674-20-5) → C12H15I2NO2

Conditions	Yield
Multi-step reaction with 5 steps 1: dimethyl sulfide borane / tetrahydrofuran 2: dichloromethane / 0.5 h 3: sodium azide / N,N-dimethyl-formamide / 20 °C 4: triphenylphosphine / water; tetrahydrofuran 5: chloroform / 20 °C View Scheme

Upstream product

• 477534-94-4 3,4-diiodo-benzaldehyde 
• 35674-29-4 2-amino-4,5-diiodo-benzoic acid 
• 619-58-9 4-iodobenzoic acid 
• 116529-62-5 4-iodo-2-nitro benzoic acid 
• 20776-54-9 2-amino-4-iodobenzoic acid 
• 101420-88-6 4-iodo-3-nitrobenzaldehyde 
• 15164-44-0 p-(iodophenyl)carboxaldehyde 
• 150-13-0 4-amino-benzoic acid 
• 2122-63-6 4-amino-3-iodobenzoic acid 

Downstream Products

• 102014-49-3 3,4-diiodo-benzoyl chloride 
• 1071750-65-6 C₁₄H₁₈I₂O₅ 
• 1418218-93-5 C₂₄H₃₁NO₅ 
• 1418218-67-3 C₇H₆I₂O 
• 1418218-68-4 C₈H₈I₂O₃S 

Relevant articles and documents

Synthesis of highly efficient pH-sensitive DNA cleaving aminomethyl N-substituted cyclic enediyne and its L-lysine conjugate

Two 10-membered benzo-fused N-substituted cyclic enediynes, one an amino methyl and the other, a C-lysine conjugated derivative 2 and 3, respectively were synthesized (as a 1.2:1 mixture of regioisomers) and their DNA-cleavage efficiency studied. Both the compounds showed much better DNA-cleavage profile than that of the parent unsubstituted enediyne 1. The lysine conjugate 3 showed an efficient pH dependent cleavage to the extent of ～50% of linear DNA formation under ambient conditions.

Easy, inexpensive and effective oxidative iodination of deactivated arenes in sulfuric acid

Two 'model' deactivated arenes, benzoic acid and nitrobenzene, were effectively monoiodinated within 1 h at 25-30 °C, with strongly electrophilic I+ reagents, prior prepared from diiodine and various oxidants (CrO3, KMnO4, active MnO2, HIO 3, NaIO3, or NaIO4) in 90% (v/v) concd sulfuric acid (ca. 75 mol% H2SO4). Next, an I2/ NaIO3/90% (v/v) concd H2SO4 exemplary system was used to effectively mono- or diiodinate a number of deactivated arenes. All former papers dealing with the direct iodination of deactivated arenes are briefly reviewed.