40932-60-3

Basic information

• Product Name: 3,5,6-Trichlorosalicylic acid
• Synonyms: 3,5,6-Trichlorosalic;Benzoic acid, 2,3,5-trichloro-6-hydroxy-;Trichlorosalicylic Aci;2-HYDROXY-3,5,6-TRICHLOROBENZOIC ACID;3,5,6-TRICHLORO-2-HYDROXYBENZOIC ACID;3,5,6-TRICHLOROSALICYLIC ACID;2,3,5-trichloro-6-hydroxy-benzoicaci;3,5,6-Trichlorosalicylic
• CAS NO: 40932-60-3
• Molecular Formula: C₇H₃Cl₃O₃
• Molecular Weight: 241.46
• EINECS: 255-144-9
• Product Categories: Aromatic Carboxylic Acids, Amides, Anilides, Anhydrides & Salts;Organic acids;Pharmaceutical Intermediate
• Mol File: 40932-60-3.mol
• Article Data: 5

Chemical Properties

• Melting Point: 209-211 °C(lit.)
• Boiling Point: 335 °C at 760 mmHg
• Flash Point: 156.4 °C
• Appearance: /
• Density: 1.772 g/cm³
• Vapor Pressure: 4.87E-05mmHg at 25°C
• Storage Temp.: Sealed in dry,Room Temperature
• Solubility: DMSO (Slightly), Methanol (Slightly)
• PKA: 1.50±0.25(Predicted)
• Water Solubility: It has limited solubility in water.
• BRN: 2940592
• CAS DataBase Reference: 3,5,6-Trichlorosalicylic acid(CAS DataBase Reference)
• NIST Chemistry Reference: 3,5,6-Trichlorosalicylic acid(40932-60-3)
• EPA Substance Registry System: 3,5,6-Trichlorosalicylic acid(40932-60-3)

Safety Data

• Hazard Codes: Xi
• Statements: 36/37/38
• Safety Statements: 26-37/39
• WGK Germany: 3
• TSCA: Yes
• Hazardous Substances Data: 40932-60-3(Hazardous Substances Data)

Usage

Uses

3,5,6-Trichlorosalicylic acid is a chlorinated salicylic acid intermediate.

InChI:InChI=1/C7H3Cl3O3/c8-2-1-3(9)6(11)4(5(2)10)7(12)13/h1,11H,(H,12,13)/p-1

Synthetic route

3,5-dichlorosalicylic acid (320-72-9) → 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3)

Conditions	Yield
With sulfuric acid; iodine; chlorine at 70℃;	93%
With sulfuric acid; iodine; chlorine at 40 - 70℃; for 6h;	81%
With sulfuric acid; chlorine

3,5-dichlorosalicylic acid (320-72-9) → 2,3,5,6-tetrachlorobenzene-1,4-diol (87-87-6) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + chloranil (118-75-2) + tri(3,5,6-trichlorosalicylide)

Conditions	Yield
With sulfuric acid; chlorine at 80 - 90℃; for 15h;	A 3.5% B 44% C 10.8% D 19%
With sulfuric acid; chlorine at 80 - 90℃; for 15h;	A 3.5% B 44% C 10.8% D n/a

sulfuric acid (7664-93-9) + 3,5-dichlorosalicylic acid (320-72-9) + chlorine (7782-50-5) → 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3)

5-chloro-2-hydroxybenzoic acid (321-14-2) → 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: chlorine / acetic acid / Ambient temperature 2: 81 percent / 65percent oleum, iodine, chlorine / 6 h / 40 - 70 °C View Scheme

5-bromosalicyclic acid (89-55-4) → 5-bromo-3-chloro-2-hydroxybenzoic acid (2200-85-3) + 4-bromo-3,6-dichlorosalicylic acid + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3)

Conditions	Yield
With trichloroisocyanuric acid; sulfuric acid; iodine at 0 - 70℃; for 5h;

salicylic acid (69-72-7) → 5-bromo-3-chloro-2-hydroxybenzoic acid (2200-85-3) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: bromine; sulfuric acid / 1 h / 20 - 60 °C 2: iodine; trichloroisocyanuric acid; sulfuric acid / 5 h / 0 - 70 °C View Scheme
Multi-step reaction with 2 steps 1: bromine; sulfuric acid / 1 h / 20 °C 2: iodine; trichloroisocyanuric acid; sulfuric acid / 5 h / 0 - 70 °C View Scheme
Multi-step reaction with 2 steps 1: bromine; sulfuric acid; acetic acid / 0.5 h / 30 - 60 °C 2: iodine; trichloroisocyanuric acid; sulfuric acid / 5 h / 0 - 70 °C View Scheme
Multi-step reaction with 2 steps 1: bromine; sulfuric acid; acetic acid / 2 h / 30 °C 2: iodine; trichloroisocyanuric acid; sulfuric acid / 5 h / 0 - 70 °C View Scheme

5-bromosalicyclic acid (89-55-4) → 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3)

Conditions	Yield
Multi-step reaction with 2 steps 1: chlorine; sulfuric acid / 8.5 h / 3 - 45 °C 2: chlorine; iodine; sulfuric acid / 3.5 h / 5 - 35 °C View Scheme

salicylic acid (69-72-7) → 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3)

Conditions	Yield
Multi-step reaction with 3 steps 1: bromine; sulfuric acid / 1.5 h / 3 - 25 °C 2: chlorine; sulfuric acid / 8.5 h / 3 - 45 °C 3: chlorine; iodine; sulfuric acid / 3.5 h / 5 - 35 °C View Scheme

5-bromo-3-chloro-2-hydroxybenzoic acid (2200-85-3) → 4-bromo-3,6-dichlorosalicylic acid + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + 3-bromo-6-((3-bromo-2,5-dichloro-6-hydroxybenzoyl)oxy)-2,5-dichlorobenzoic acid

Conditions	Yield
With sulfuric acid; iodine; chlorine at 5 - 35℃; for 3.5h;

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + cyclohexylmethyl alcohol (100-49-2) → C14H15Cl3O3

Conditions	Yield
titanium (IV) oxide bis(2,4-pentanedionate) In xylene Reflux;	99%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + benzylamine (100-46-9) → C7H9N*C7H3Cl3O3

Conditions	Yield
In methanol for 0.0833333h;	83.19%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + trimethyltin(IV)chloride (1066-45-1) → C7HCl3O3(2-)*2Sn(4+)*6CH3(1-)

Conditions	Yield
With sodium ethanolate In methanol at 40℃; for 12h; Inert atmosphere;	77%

dmap (1122-58-3) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → C7H10N2*C7H3Cl3O3

Conditions	Yield
In methanol; ethanol	77%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + benzyl alcohol (100-51-6) → C14H9Cl3O3 (1330007-24-3)

Conditions	Yield
titanium (IV) oxide bis(2,4-pentanedionate) In toluene Reflux;	76.5%

cadmium(II) perchlorate hydrate + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + N'-(amino(pyrimidin-2-yl)methylene)-3-(pyridin-2-yl)-1H-pyrazole-5-carbohydrazide → 2C7H2Cl3O3(1-)*4C7H3Cl3O3*5H2O*9Cd(2+)*8C14H10N8O(2-)

Conditions	Yield
In methanol; N,N-dimethyl-formamide at 80℃; for 12h;	74%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + tributyltin chloride (1461-22-9) → C7HCl3O3(2-)*2Sn(4+)*6C4H9(1-)

Conditions	Yield
With sodium ethanolate In methanol at 40℃; for 12h; Inert atmosphere;	72%

3,5-dihydroxyphenol (108-73-6) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → 5,7,8-trichloro-1,3-dihydroxyxanthone

Conditions	Yield
With methanesulfonic acid; phosphorus pentoxide at 90℃; for 0.333333h; Temperature;	72%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + butan-1-ol (71-36-3) → butyl 3,5,6-trichlorosalicylate (30431-49-3)

Conditions	Yield
With sulfuric acid for 24h; Heating;	67%

orcinol (504-15-4) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → 1,2,4-trichloro-8-hydroxy-6-methyl-9H-xanthen-9-one

Conditions	Yield
With methanesulfonic acid; phosphorus pentoxide at 90℃;	66%

zirconocene dichloride (1291-32-3) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → [Cp2Zr(μ2-O',O''C-C6H(OH)Cl3)2]

Conditions	Yield
In hydrogenchloride; dichloromethane mixt. of zirconocene dichloride in 1 M aq. HCl and dichlorobenzoic acidin CH2Cl2 was stirred for 30 min at room temp.; organic layer was separated, dried over MgSO4, filtered, concd. in vac.,crystd. form CH2Cl2/hexane, elem. anal.;	64.4%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + water (7732-18-5) + copper(II) salt → diaqua-di(3,5,6-trichlorosalicylato)copper(II)

Conditions	Yield
With ammonia In methanol at 70℃; for 3.5h; pH=Ca. 7;	55.16%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + water (7732-18-5) + cobalt(II) salt → diaqua-3,5,6-trichlorosalicylatocobalt(II)

Conditions	Yield
With ammonia In methanol at 70℃; for 3.5h; pH=Ca. 7;	54.12%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + water (7732-18-5) + nickel(II) salt → diaqua-3,5,6-trichlorosalicylatonickel(II)

Conditions	Yield
With ammonia In methanol at 70℃; for 3.5h; pH=Ca. 7;	54.11%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + water (7732-18-5) + iron(II) salt → diaqua-di(3,5,6-trichlorosalicylato)iron(II)

Conditions	Yield
With ammonia In methanol at 70℃; for 3.5h; pH=Ca. 7;	53.86%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + water (7732-18-5) + mangnese(II) salt → diaqua-3,5,6-trichlorosalicylatomangnese(II)

Conditions	Yield
With ammonia In methanol at 70℃; for 3.5h; pH=Ca. 7;	53.65%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → diaqua-3,5,6-trichlorosalicylatocalcium(II)

Conditions	Yield
With ammonia; water In methanol at 70℃; for 3.5h; pH=Ca. 7;	52.45%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + water (7732-18-5) + zinc(II) salt → diaqua-3,5,6-trichlorosalicylatozinc(II)

Conditions	Yield
With ammonia In methanol at 70℃; for 3.5h; pH=Ca. 7;	52.16%

octanol (111-87-5) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → octyl 3,5,6-trichlorosalicylate (71527-66-7)

Conditions	Yield
With sulfuric acid for 24h; Heating;	52%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → diaqua-3,5,6-trichlorosalicylatomagnessium(II)

Conditions	Yield
With ammonia; water In methanol at 70℃; for 3.5h; pH=Ca. 7;	51.06%

i-Amyl alcohol (123-51-3) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → 3'-methylbutyl 3,5,6-trichlorosalicylate (71527-65-6)

Conditions	Yield
With sulfuric acid for 24h; Heating;	48%

pentan-1-ol (71-41-0) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → pentyl 3,5,6-trichlorosalicylate (30431-53-9)

Conditions	Yield
With sulfuric acid for 24h; Heating;	43%

2,5-dimethyl-pyrazine (123-32-0) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → C6H8N2*2C7H3Cl3O3

Conditions	Yield
In ethanol at 20℃;	36.1%

2,3-dimethylpyrazine (5910-89-4) + 3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → C6H8N2*C7H3Cl3O3

Conditions	Yield
In ethanol at 20℃;	33.5%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) + boric acid (11113-50-1) + lithium carbonate (554-13-2) → lithium bis[3,5,6-trichlorosalicylato(2-)]borate

Conditions	Yield
In neat (no solvent) reacted; recrystd. four times from acetonitrile;	30%

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → 2-bromo-3,4,6-trichloro-phenol (4524-78-1)

Conditions	Yield
With bromine; acetic acid at 60℃;

3,5,6-Trichloro-2-hydroxybenzoic acid (40932-60-3) → 4-bromo-2,3,5-trichloro-6-hydroxy-benzoic acid (693259-01-7)

Conditions	Yield
With sulfuric acid; bromine

Upstream product

• 7664-93-9 sulfuric acid 
• 320-72-9 3,5-dichlorosalicylic acid 
• 7782-50-5 chlorine 
• 2200-85-3 5-bromo-3-chloro-2-hydroxybenzoic acid 
• 69-72-7 salicylic acid 
• 89-55-4 5-bromosalicyclic acid 
• 321-14-2 5-chloro-2-hydroxybenzoic acid 

Downstream Products

• 111217-18-6 Methyl 3,5,6-trichlorosalicylate 
• 2307-49-5 3,5,6-trichloro-2-methoxybenzoic acid 
• 69954-01-4 2,3,5-trichloro-6-methoxybenzoic acid chloride 
• 14386-55-1 methyl 2,3,5-trichloro-2 methoxybenzoate 
• 1330007-24-3 C₁₄H₉Cl₃O₃ 
• 1244382-45-3 bis{3,4,6-trichloro-2-[(phenylmethoxy)carbonyl]phenyl} oxalate 
• 1000397-70-5 C₁₃H₈Cl₃NO₂ 
• 1000397-65-8 C₁₅H₁₂Cl₃NO₂ 

Relevant articles and documents

A new process to prepare 3,6-dichloro-2-hydroxybenzoic acid, the penultimate intermediate in the synthesis of herbicide dicamba

Glyphosate [N-(phosphonomethyl)glycine] is a broad spectrum, post-emergent herbicide that is among the most widely used agrochemicals globally. Over the past 30 years, there has been a development of glyphosate-resistant weeds, which pose a significant challenge to growers and crop scientists, resulting in lower crop yields and increased costs. 3,6-Dichloro-2-methoxybenzoic acid (dicamba) is the active ingredient in XtendiMax a standalone herbicide developed by Bayer Crop Science to control broadleaf weeds, including glyphosate-resistant species. 3,6-Dichloro-2-hydroxybenzoic acid (3,6-DCSA) is the penultimate intermediate in the synthesis of dicamba. Existing dicamba manufacturing routes utilize a high temperature, high pressure Kolbe-Schmitt carboxylation to prepare 3,6-DCSA. Described in this Letter is a new, non-Kolbe-Schmitt process to prepare 3,6-DCSA from salicylic acid in four chemical steps.

Process for preparing esters of 3,5,6-trichlorosalicyclic acid

An improved process for the synthesis of esters of 3,5,6-trichlorosalicylic acid in quantitative yield comprises reacting the acid with an alcohol under distillation conditions in the presence of a titanium ester or chelate catalyst, whereby byproduct ether formation from the alcohol is suppressed. The process is especially applicable to a process by which salicylic acid is chlorinated first in concentrated sulfuric acid and then with iodine catalyst to make the trichlorosalicylic acid which is extracted and then reacted with an alcohol and a titanium catalyst to make the ester.

Processes for preparing 3,5,6-trichlorosalicylic acid and esters thereof

An improved single-pot process for synthesis of 3,5,6-trichlorosalicylic acid and esters thereof is described. Salicylic acid is chlorinated first in concentrated sulfuric acid and then with iodine catalyst to make the trichlorosalicylic acid which is extracted and then reacted with an alcohol to make the ester.