4440-40-8

Basic information

• Product Name: 2,4,6-Cycloheptatriene-1-carboxylic acid
• Synonyms: 2,4,6-Cycloheptatriene-1-carboxylic acid;cyclohepta-2,4,6-trienecarboxylic acid;cyclohepta-1,3,5-triene-7-carboxylic acid;Cyclohepta-2,4,6-triencarbonsaeure;1,3,5-cycloheptatriene-7-carboxylic acid
• CAS NO: 4440-40-8
• Molecular Formula: C8H8O2
• Molecular Weight: 136.15
• Mol File: 4440-40-8.mol
• Article Data: 2

Chemical Properties

• CAS DataBase Reference: 2,4,6-Cycloheptatriene-1-carboxylic acid(CAS DataBase Reference)
• NIST Chemistry Reference: 2,4,6-Cycloheptatriene-1-carboxylic acid(4440-40-8)
• EPA Substance Registry System: 2,4,6-Cycloheptatriene-1-carboxylic acid(4440-40-8)

Safety Data

• Hazardous Substances Data: 4440-40-8(Hazardous Substances Data)

Usage

General Description

2,4,6-Cycloheptatriene-1-carboxylic acid is a chemical compound with the molecular formula C8H6O2. It is a carboxylic acid derivative of cycloheptatriene, containing a carboxylic acid functional group at the 1 position. 2,4,6-Cycloheptatriene-1-carboxylic acid is an aromatic carboxylic acid, with a six-membered ring and a double bond, giving it aromatic properties. It is commonly used in organic synthesis and as a building block for the production of various pharmaceuticals, agrochemicals, and materials. Additionally, it is known for its aromatic and reactive properties, making it useful in the development of new chemical compounds and materials.

Synthetic route

ethyl cyclohepta-2,4,6-trienecarboxylate (27332-37-2) → cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8)

Conditions	Yield
With water; sodium hydrogencarbonate In methanol for 2h; Heating;	74%
With sodium hydrogencarbonate In methanol; water for 2h; Heating;	64%
With sulfuric acid; acetone

cyclohepta-2,4,6-triene-1-carbonitrile (13612-59-4) → cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8)

Conditions	Yield
With hydrogenchloride; methanol; diethyl ether anschliessend mit H2O behandeln und Behandeln des Reaktionsprodukts mit NaHCO3 in wss. Methanol und anschliessend mit wss. NaOH;
Multi-step reaction with 2 steps 1: 46.3 percent / conc. H2SO4 / 35 h / Heating 2: 74 percent / HaHCO3, H2O / methanol / 2 h / Heating View Scheme
Multi-step reaction with 2 steps 1: HCl 2: aq. NaOH, NaHCO3 / methanol View Scheme
Multi-step reaction with 2 steps 2: aq. H2SO4 View Scheme

cyclohepta-2,4,6-trienecarboxamide (26902-48-7) → cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8)

Conditions	Yield
With sulfuric acid

7-(methoxycarbonyl)cycloheptatriene (32399-46-5) → cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8)

Conditions	Yield
With sodium hydroxide; sodium hydrogencarbonate In methanol

cyclohepta-2,4,6-trienecarboxylic acid amide → cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8)

Conditions	Yield
With sulfuric acid at 120℃;

7-ethoxy-1,3,5-cycloheptatriene (1714-39-2) → cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8)

Conditions	Yield
Multi-step reaction with 3 steps 1: aq. HCl 3: aq. H2SO4 View Scheme

9-fluorenone (486-25-9) + cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → 7-(9-Hydroxy-9-fluorenyl)-1,3,5-cycloheptatriene-2-carboxylic acid (91894-20-1)

Conditions	Yield
With lithium diisopropyl amide In tetrahydrofuran 1) -78 deg C, 1 h, 2) to r.t.;	83%

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → meso--3,3'-dicarbonsaeure + -4,4'-dicarbonsaeure

Conditions	Yield
With n-butyllithium; iodine In tetrahydrofuran; hexane -78 deg C to r.t.; Yields of byproduct given;	A 4% B n/a
With n-butyllithium; iodine In tetrahydrofuran; hexane -78 deg C to r.t.; Yield given. Title compound not separated from byproducts;	A 4% B n/a

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → tropylium tetrafluoroborate (27081-10-3)

Conditions	Yield
With chloroform; acetyl tetrafluoroborate

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → carboxy-cycloheptatrienylium; bromide

Conditions	Yield
With bromine; chlorobenzene

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → cycloheptatriene-2-carboxylic acid (26902-51-2)

Conditions	Yield
With sodium hydroxide at 38.4 - 76.6℃; Kinetics;

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → 2-Carboxy-7-deuteriocycloheptatrien (26902-52-3)

Conditions	Yield
With deuteriated sodium hydroxide In water-d2

4-Phenylurazole (15988-11-1) + cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → 3,3-dicarboxy-N-phenyl-6,7-diazatricyclo<3.2.2.02,4>non-8-ene-6,7-dicarboximide (109764-59-2)

Conditions	Yield
With hydrogenchloride; n-butyllithium 1) THF, hexane, -78 deg C, 30 min, 2) 30 min; Yield given. Multistep reaction;

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) + 2-methoxy-ethyl p-toluenesulfonyloxy ester (17178-10-8) → 7-(2-Methoxyethyl)-1,3,5-cycloheptatrien-7-carbonsaeure (81003-57-8)

Conditions	Yield
With lithium diisopropyl amide 1.) acetone, hexane, THF, -60 - -50 deg C, 2 h, 2.) THF, r.t., overnight; Yield given. Multistep reaction;

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) + 1,2-bis-tosyloxyethane (6315-52-2) → Spiro<1,3,5-cycloheptatrien-7,3'-tetrahydrofuran>-2'-on (63227-71-4)

Conditions	Yield
With lithium diisopropyl amide 1.) THF, hexane, -60 deg C, 2.) THF, r.t., overnight; Yield given. Multistep reaction;

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) + methylamine hydrochloride (593-51-1) → 8-methyl-nortrop-2-ene-2-carboxylic acid (127379-23-1)

Conditions	Yield
With sodium hydroxide at 150℃; under 103430 Torr; for 6h;

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → cyclohepta-1,3,6-trienecarboxylic acid (21297-55-2) + cycloheptatriene-2-carboxylic acid (26902-51-2)

Conditions	Yield
With tri-n-propylamine In tetrahydrofuran at 110℃; for 30h; Rate constant; other temp. and time;
With N-ethyl-N,N-diisopropylamine In acetonitrile at 110℃; for 29h; Yield given. Yields of byproduct given. Title compound not separated from byproducts;

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → Dilithium-heptafulven-8,8-diolat (85540-38-1)

Conditions	Yield
With n-butyllithium In tetrahydrofuran; hexane at -78℃;
With n-butyllithium In tetrahydrofuran

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) + methyl iodide (74-88-4) → meso--3,3'-dicarbonsaeure-dimethylester (89548-91-4) + Bicycloheptyl-2,4,6,2',4',6'-hexaene-4,4'-dicarboxylic acid dimethyl ester

Conditions	Yield
Yield given. Multistep reaction;
Multistep reaction. Yields of byproduct given;

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → cycloheptatriene-7-carbonyl chloride (32399-48-7)

Conditions	Yield
With thionyl chloride
With thionyl chloride for 42h; Ambient temperature;
With thionyl chloride

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → 7-Carboxy-7-deuteriocycloheptatrien (26902-49-8)

Conditions	Yield
With water-d2; sulfuric acid-d2 at 108℃; for 10h;
Multi-step reaction with 2 steps 1: 15 percent BuLi / tetrahydrofuran; hexane / -78 °C 2: D2O View Scheme

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → 2,4,6-Cycloheptatrien-1-carbonsaeure-dimethylamid (32399-49-8)

Conditions	Yield
Multi-step reaction with 2 steps 1: SOCl2 / 42 h / Ambient temperature 2: diethyl ether / 1 h View Scheme

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → barbaralone-d1 (35332-67-3)

Conditions	Yield
Multi-step reaction with 4 steps 1: D2O, D2SO4 / 10 h / 108 °C 2: SOCl2 4: CuSO4 View Scheme

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → 7-deuterio-1,3,5-cycloheptatrien-7-carbonyl chloride

Conditions	Yield
Multi-step reaction with 2 steps 1: D2O, D2SO4 / 10 h / 108 °C 2: SOCl2 View Scheme

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → C9H7(2)HN2O

Conditions	Yield
Multi-step reaction with 3 steps 1: D2O, D2SO4 / 10 h / 108 °C 2: SOCl2 View Scheme

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → meso--3,3'-dicarbonsaeure

Conditions	Yield
Multi-step reaction with 2 steps 2: 90 percent / NaOH / H2O; methanol / 120 h / 45 °C View Scheme

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → (+/-)-Ecgonidine methyl ester (127379-24-2)

Conditions	Yield
Multi-step reaction with 2 steps 1: aq. NaOH / 6 h / 150 °C / 103430 Torr 2: concd H2SO4 / 24 h / Heating View Scheme

cyclohepta-2,4,6-trienecarboxylic acid (4440-40-8) → cyclohepta-2,4,6-trienecarboxamide (26902-48-7)

Conditions	Yield
Multi-step reaction with 3 steps 1: SOCl2 2: Py / petroleum ether / -50 °C 3: NaNH2 / diethyl ether / -60 °C View Scheme
Multi-step reaction with 2 steps 1: SOCl2 2: aq. NH3 View Scheme

Upstream product

• 1714-39-2 7-ethoxy-1,3,5-cycloheptatriene 
• 32399-46-5 7-(methoxycarbonyl)cycloheptatriene 
• 26902-48-7 cyclohepta-2,4,6-trienecarboxamide 
• 27332-37-2 ethyl cyclohepta-2,4,6-trienecarboxylate 
• 13612-59-4 cyclohepta-2,4,6-triene-1-carbonitrile 

Downstream Products

• 27081-10-3 tropylium tetrafluoroborate 
• 26902-48-7 cyclohepta-2,4,6-trienecarboxamide 
• 32399-49-8 N,N-dimethyl-1,3,5-cycloheptatriene-7-carboxamide 
• 32399-48-7 cycloheptatriene-7-carbonyl chloride 
• 109764-59-2 3,3-dicarboxy-N-phenyl-6,7-diazatricyclo<3.2.2.0^2,4>non-8-ene-6,7-dicarboximide 

Relevant articles and documents

Heptafulvenone, vinylketene, butadienylketene, and allenylketene - Facile generation, observation, and radical reaction with TEMPO

Heptafulvenone (1), vinylketene (11), 1,3-butadienylketene [(E)-15], and allenylketene (21) have been prepared by reaction of the corresponding acyl chlorides with 1,8-bis(dimethylamino)naphthalene as long-lived species in solution at room temperature, and their ketenyl IR bands observed under these conditions for the first time, at 2101, 2118, 2111, 2117 cm-1, respectively. These unsaturated ketenes react with tetramethylpiperidinyloxyl (TEMPO, TO.) with initial attack at the carbonyl carbon giving delocalized radicals which give from 1 a mixture of the ring contracted o-, m-, and p-formylbenzoates O=CHC6H4CO2T (6) and the bis-(cycloheptatrienyl) dimer 7. The products from 11, (E)-15, and 21 are the bis(TEMPO) adducts (E,Z)-TOCH2CH= CHCO2T (12), (E,E)-TOCH2CH=CHCH=CHCO2T (17), and (E,Z)-CH2=C(OT)CH=CHCO2T (22), respectively.