14187-32-7

Basic information

• Product Name: Dibenzo-18-crown-6
• Synonyms: CROWN ETHER/DIBENZO-18-CROWN-6;DIBENZO-18-CROWN-6;DIBENZO-18-CROWN 6-ETHER;2,3,11,12-DIBENZO-1,4,7,10,13,16-HEXAOXACYCLOOCTADECA-2,11-DIENE;1,4,7,14,17,20-HEXAOXA-[7.7]ORTHOCYCLOPHANE;6,7,9,10,17,18,20,21-OCTAHYDRODIBENZO;6,7,9,10,17,18,20,21-OCTAHYDRODIBENZO[B,K][1,4,7,10,13,16]HEXAOXACY-CLOOCTADECENE;2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclooctadeca-2,11-diene,dibenzo-18-crown-6
• CAS NO: 14187-32-7
• Molecular Formula: C₂₀H₂₄O₆
• Molecular Weight: 360.4
• EINECS: 238-041-3
• Product Categories: API intermediates;Crown Ethers;Functional Materials;Macrocycles for Host-Guest Chemistry;crown ether
• Mol File: 14187-32-7.mol
• Article Data: 12

Chemical Properties

• Melting Point: 162-164 °C(lit.)
• Boiling Point: 380-384 °C (679 mmHg)
• Flash Point: 380-384°C/679mm
• Appearance: White to slightly beige/Fluffy Powder
• Density: 1.1801 (rough estimate)
• Vapor Pressure: 3.65E-10mmHg at 25°C
• Refractive Index: 1.5200 (estimate)
• Storage Temp.: Store below +30°C.
• Solubility: 0.007g/l
• Water Solubility: sparingly soluble
• Sensitive: air sensitive
• Merck: 14,2602
• BRN: 1162153
• CAS DataBase Reference: Dibenzo-18-crown-6(CAS DataBase Reference)
• NIST Chemistry Reference: Dibenzo-18-crown-6(14187-32-7)
• EPA Substance Registry System: Dibenzo-18-crown-6(14187-32-7)

Safety Data

• Hazard Codes: Xi,Xn
• Statements: 36-36/37/38-20/21/22
• Safety Statements: 26-37/39-36
• WGK Germany: 2
• RTECS: HP5386000
• TSCA: Yes
• Hazardous Substances Data: 14187-32-7(Hazardous Substances Data)

Usage

Chemical Properties

white to slightly beige fluffy powder

Uses

Different sources of media describe the Uses of 14187-32-7 differently. You can refer to the following data:
1. Dibenzo-18-crown-6, is used as an important raw material and intermediate used in organic Synthesis, pharmaceuticals, agrochemicals and dyestuff. It is an important organic intermediate.
2. Crown ether/Dibenzo-18-crown-6 for synthesis. CAS 14187-32-7, molar mass 360.41 g/mol.

Purification Methods

Crystallise it from *benzene, n-heptane or toluene and dry it under vacuum at room temperature for several days. [Szezygiel J Phys Chem 91 1252 1987, V.gtle ed. Top Corr Chem (Host Guest Complex Chemistry) 98 1981.]

InChI:InChI=1/C20H24O6/c1-3-7-19-17(5-1)24-15-13-22-11-9-21-10-12-23-14-16-25-18-6-2-4-8-20(18)26-19/h1-8H,9-16H2

Synthetic route

benzene-1,2-diol (120-80-9) + 3-oxa-1,5-dichloropentane (111-44-4) → dibenzo-18-crown-6 (14187-32-7)

Conditions	Yield
With potassium hydroxide In dimethyl sulfoxide for 0.0833333h; Microwave irradiation;	79%
With potassium carbonate In N,N-dimethyl-formamide for 24h; Reflux;	21%
Stage #1: benzene-1,2-diol; 3-oxa-1,5-dichloropentane With sodium hydroxide In butan-1-ol at 90℃; for 2h; Heating; Stage #2: With sodium hydroxide for 16h; Reflux; Inert atmosphere;	3.47%
With potassium carbonate In butan-1-ol at 115℃;
With sodium hydroxide In dimethyl sulfoxide

bis(2-hydroxyphenoxyethyl)ether (23116-94-1) + 3-oxa-1,5-dichloropentane (111-44-4) → dibenzo-18-crown-6 (14187-32-7)

Conditions	Yield
With potassium hydroxide In dimethyl sulfoxide for 0.0833333h; Microwave irradiation;	73%
With potassium carbonate In acetonitrile at 85℃; for 36h;	69%
With sodium hydroxide 1.) n-BuOH, MeOH, 2.) n-BuOH, reflux, 17 h; Yield given. Multistep reaction;

benzene-1,2-diol (120-80-9) + 3-oxa-1,5-dichloropentane (111-44-4) → dibenzo-18-crown-6 (14187-32-7) + 1,2-bis[2'-(2''-chloroethoxy)ethoxy]benzene (41758-00-3) + 2-(5-chloro-3-oxa-1-pentyloxy)phenol (111875-63-9)

Conditions	Yield
With potassium hydroxide In dimethyl sulfoxide at 90℃; for 2.5h; Yields of byproduct given;	A 55% B n/a C n/a

6,7,9,10,17,18,20,21-Octahydro-5,8,11,16,19,22-hexaoxa-dibenzo[a,j]cyclooctadecene; compound with GENERIC INORGANIC NEUTRAL COMPONENT → dibenzo-18-crown-6 (14187-32-7)

Conditions	Yield
With Iodine monochloride In benzene at 24.9℃; Equilibrium constant;

C20H24O6*C4H10N2*2ClH → dibenzo-18-crown-6 (14187-32-7) + piperazine dihydrochloride (142-64-3)

Conditions	Yield
In water at 25℃; Equilibrium constant;

C20H24O6*C6H12N2*2ClH → dibenzo-18-crown-6 (14187-32-7) + 1,4-diaza-bicyclo[2.2.2]octane dihydrochloride (49563-87-3)

Conditions	Yield
In water at 25℃; Equilibrium constant;

dibenzo-18-crown-6 (14187-32-7) → 4,4',5,5'-tetrabromodibenzo-18-crown-6 ether (40100-11-6)

Conditions	Yield
With bromine; acetic acid In water Reflux;	100%
With bromine; acetic acid for 5h; Heating;	90%
With bromine; acetic acid at 95℃; for 12h; Bromination;	80%

dibenzo-18-crown-6 (14187-32-7) → 20,25-dinitro-2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclooctadeca-2,11-diene (32082-46-5)

Conditions	Yield
With nitric acid; lanthanum(III) nitrate In acetonitrile at 80℃; for 0.5h; nitrates of oth. metals;	100%
With nitric acid; acetic anhydride In chloroform; acetic acid at 50℃; for 5h; Reagent/catalyst; Temperature;

dibenzo-18-crown-6 (14187-32-7) → 2,3,12,13-tetranitro-6,7,9,10,17,18,20,21-octahydro-5,8,11,16,19,22-hexaoxadibenzo[b,k]cyclooctadecene (61853-51-8)

Conditions	Yield
With sulfuric acid; nitric acid In dichloromethane at 20℃; for 12h;	100%
With nitric acid	96%
With sulfuric acid; nitric acid In dichloromethane at 20℃; for 48h;	96%

tetrahydrofuran (109-99-9) + dibenzo-18-crown-6 (14187-32-7) → (borohydrido)(dibenzo-18-crown-6)(tetrahydrofuran)potassium

Conditions	Yield
With potassium borohydride for 528h; Heating;	100%

dibenzo-18-crown-6 (14187-32-7) + 1-methoxy-4-(2-nitro-vinyl)-benzene (3179-10-0) → 4',4"(5")-(dibenzo-18-crown-6)di-4-methoxyphenylacetohydroxamic acid

Conditions	Yield
With PPA for 1h; Heating;	100%

dibenzo-18-crown-6 (14187-32-7) + sodium phenylsulfonate (515-42-4) → C20H24O6*C6H5O3S(1-)*Na(1+)

Conditions	Yield
In methanol at 60℃; for 1h;	100%

dibenzo-18-crown-6 (14187-32-7) + sodium 3-nitrobenzenesulfonate (127-68-4) → C20H24O6*C6H4NO5S(1-)*Na(1+)

Conditions	Yield
In methanol at 60℃; for 1h;	100%

dibenzo-18-crown-6 (14187-32-7) + sodium tosylate (657-84-1) → C20H24O6*C7H7O3S(1-)*Na(1+)

Conditions	Yield
In methanol at 60℃; for 1h;	100%

dibenzo-18-crown-6 (14187-32-7) + [1,2,5]thiadiazolo[3,4-c][1,2,5]thiadiazole (55904-34-2) → C20H24O6*C2N4S2

Conditions	Yield
In dichloromethane at 20℃;	100%

dibenzo-18-crown-6 (14187-32-7) + 1-selena-2,5-diaza-2,4-cyclopentadiene-3,4-dicarbonitrile (106013-47-2) → C4N4Se*C20H24O6

Conditions	Yield
In dichloromethane at 20℃;	100%

dibenzo-18-crown-6 (14187-32-7) + potassium decacyanodicobaltate → (dibenzo-18-crown-6)potassium pentacyanocobaltate(II)

Conditions	Yield
In methanol Ar-atmosphere; stirring; filtration, evapn. (40°C, crystn. on walls of the vessel);	99%
In methanol Ar-atmosphere; stirring; filtration, pptn. on ether addn., filtration, washing (MeOH/ether = 1/2,then ether), drying (vac., 40°C); elem. anal.;	87%

tetrahydrofuran (109-99-9) + dibenzo-18-crown-6 (14187-32-7) + potassium borohydride → (borohydrido)(1,4,7,10,13,16-hexaoxa-2,3:11,12-dibenzocyclooctadeca-2,11-diene-κ(6)O)(tetrahydrofuran)potassium (927437-38-5)

Conditions	Yield
In tetrahydrofuran an NMR tube charged with KBH4, dibenzo-18-crown-6 and THF, refluxed for 22 d;	99%

dibenzo-18-crown-6 (14187-32-7) + potassium tetrakis(allyl)gallate (1356843-06-5) → [K(dibenzo-18-crown-6)][Ga(η1-allyl)4] (1356843-08-7)

Conditions	Yield
In tetrahydrofuran under Ar, Schlenk techniques; dibenzocrown in THF added to soln. of Ga compd. in THF; volatiles removed (reduced pressure), pentane added to oil, supernatant decanted, residue washed (pentane), solid dried (vac.); elem. anal., XRD;	99%

dibenzo-18-crown-6 (14187-32-7) + [Al(η1-allyl)3(THF)] (1253215-98-3) + allyl potassium (60647-46-3, 7329-38-6) → [K(dibenzo-18-crown-6][tetrakis(η1-allyl)aluminate] (1320213-77-1)

Conditions	Yield
In tetrahydrofuran under Ar, Schlenk technique; addn. of allylpotassium and dibenzo-18-crown-6 to soln. of Al complex in THF; evapn. under vac., oily residue washed with pentane, solid dried under vac.; elem. anal.;	98%

methanol (67-56-1) + dibenzo-18-crown-6 (14187-32-7) → C20H24O6*CH4O*6HO(1-)*6K(1+)

Conditions	Yield
With potassium hydroxide at 60℃; for 1h;	97.9%

dibenzo-18-crown-6 (14187-32-7) + diphenyliodonium hexafluorophosphate (58109-40-3) → diphenyliodonium hexafluorophosphate-dibenzo-18-crown-6 ether complex

Conditions	Yield
In ethyl acetate for 0.0833333h; Reflux;	97.6%

1,3-DIOXOLANE (646-06-0) + dibenzo-18-crown-6 (14187-32-7) + sodium thiocyanide (540-72-7) → C20H24O6*C3H6O2*CNS(1-)*Na(1+)

Conditions	Yield
for 1h; Ambient temperature;	97%

dibenzo-18-crown-6 (14187-32-7) + (2-nitroethenyl)benzene (102-96-5) → 4',4"(5")-(dibenzo-18-crown-6)diphenylacetohydroxamic acid

Conditions	Yield
With PPA for 2h; Heating;	97%

dibenzo-18-crown-6 (14187-32-7) + niobium pentachloride → NbCl5(dibenzo-18-crown-6)

Conditions	Yield
In dichloromethane Ar-atmosphere; molar ratio Nb2Cl10:crown=1:2, room temp.; elem. anal.;	97%

tetrahydrofuran (109-99-9) + dibenzo-18-crown-6 (14187-32-7) + [sodium phosphaethynolate•(dioxane)2.5] → [sodium(phosphaethynolate)(dibenzo-18-crown-6)(tetrahydrofuran)]

Conditions	Yield
at 20℃; for 12h; Inert atmosphere;	97%

dibenzo-18-crown-6 (14187-32-7) + dichloro(mesitylene)ruthenium(II) dimer + nitromethane (75-52-5) + silver trifluoromethanesulfonate (2923-28-6) → (η6-1,3,5-C6H3Me3)Ru(η6-dibenzo-18-crown-6)(OTf)2

Conditions	Yield
In nitromethane byproducts: AgCl; (Ar), mixt. of Ru complex and AgOTf (1:4) stirred for 1 h in CH3NO2, AgCl filtered off, treated with 2 equiv. of dibenzo-18-crown-6, refluxed for 8 h; filtered, evapd.(vac.), washed (CH2Cl2), dissolved (acetone), chromy.(Al2O3 - acetone/EtOH 1:1), concd., pptd.(Et2O), elem. anal.;	96%

dibenzo-18-crown-6 (14187-32-7) + tert-butyl alcohol (75-65-0) → 4'-tert-Butyldibenzo-18-crown-6 (75264-22-1)

Conditions	Yield
With sulfuric acid; sodium perchlorate In chloroform Heating; or KClO4;	95%

dibenzo-18-crown-6 (14187-32-7) + acetic anhydride (108-24-7) → 1,1'-(6,7,9,10,17,18,20,21-octahydrodibenzo[b,k]-[1,4,7,10,13,16]hexaoxacyclooctadecine-2,13-diyl)diethanone (67722-66-1)

Conditions	Yield
With phosphoric acid at 60℃; for 4h; Temperature;	95%
With acetic acid at 96 - 100℃; for 1h;	87%

dibenzo-18-crown-6 (14187-32-7) + tris(pivaloyltrifluoroacetonate)erbium(III) aquate → tris(pivaloyltrifluoroacetonate) erbium(III)*dibenzo-18-crown-6

Conditions	Yield
In neat (no solvent) heated to 100°C; dibenzo-18-crown-6 added with stirring; stirred for 5-10 min;; washed (water); filtered; dried at room temp.; sublimated (vac.); elem. anal.;;	95%

dibenzo-18-crown-6 (14187-32-7) + zinc borohydride → 2Zn(2+)*4(BH4)(1-)*(C6H4O)2(OCH2CH2)4 = (Zn(BH4)2)2*(C6H4O)2(OCH2CH2)4

Conditions	Yield
In diethyl ether under inert atm.; dibenzo-18-crown-6 added to soln. of Zn(BH4)2 in diethyl ether, stirred for 10 h; filtered off, washed (diethyl ether); elem. anal., DTA;	95%
In tetrahydrofuran

dibenzo-18-crown-6 (14187-32-7) + zinc(II) tetrahydroborate → zinc borohydride dibenzo-18-crown-6 adduct

Conditions	Yield
In diethyl ether inert atmosphere; crown ether addn. to soln. of B-compd., stirring (10 h); ppt. filtration off, washing (diethyl ether), vacuum drying; elem. anal.;	95%
In diethyl ether stirring (room temp., 10 h, pptn.); filtration, washing (ether), drying (vac., room temp., 20 h); elem. anal.;	90%

dibenzo-18-crown-6 (14187-32-7) + [((t)Bu3SiO)Cr(μ-OSi(t)Bu3)2]Na * benzene (851625-22-4) → [((t)Bu3SiO)3Cr][Na(dibenzo-18-crown-6)] (851625-24-6)

Conditions	Yield
In benzene dibenzo-18-crown-6 added to a soln. of Cr complex; crystd. for 12 h; elem. anal.;	95%

dibenzo-18-crown-6 (14187-32-7) → 4,4'-dibromodibenzo-18-crown-6 ether (110692-06-3)

Conditions	Yield
With N-Bromosuccinimide In chloroform at 20℃;	94%

dibenzo-18-crown-6 (14187-32-7) → 2,13-Diiodo-6,7,9,10,17,18,20,21-octahydro-5,8,11,16,19,22-hexaoxa-dibenzo[a,j]cyclooctadecene (134403-52-4)

Conditions	Yield
With sulfuric acid; dihydrogen peroxide; iodine In ethanol for 4h; Heating;	94%

dibenzo-18-crown-6 (14187-32-7) + Nd-trispivaloyltrifluoroacetonate*2H2O → tris(pivaloyltrifluoroacetonate) neodymium(III)*dibenzo-18-crown-6

Conditions	Yield
In chloroform boiled for 1 h;; evapd. in air at room temp.; washed (H2O); filtered; dried; sublimated (vac.); elem. anal.;;	94%

Upstream product

• 82645-24-7 1,5-bis(benzaldehydeoxy)-3-oxopentane 
• 90-02-8 salicylaldehyde 
• 120-80-9 benzene-1,2-diol 
• 111-44-4 3-oxa-1,5-dichloropentane 
• 23116-94-1 bis(2-hydroxyphenoxyethyl)ether 

Downstream Products

• 67967-49-1 1-(14-Propionyl-6,7,9,10,17,18,20,21-octahydro-5,8,11,16,19,22-hexaoxa-dibenzo[a,j]cyclooctadecen-2-yl)-propan-1-one 
• 67967-47-9 4',4''(5'')-dipropionyl-dibenzo-18-crown-6 
• 106508-99-0 trans-bis(p-toluenesulfonamido)dibenzo-18-crown-6 
• 106509-00-6 C₆₆H₆₆N₂O₁₄S₂ 
• 293300-55-7 cis-di((4-nitrophenylcarboxamido)benzo)-18-crown-6 
• 126531-26-8 6,7,9,10,17,18,20,21-octahydro-5,8,11,16,19,22-hexaoxadibenzo[a,j]cyclooctadecen-2-yl amine 
• 118060-27-8 20-nitro-2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxa-2,11-cyclooctadecadiene 
• 32082-46-5 20,25-dinitro-2,3,11,12-dibenzo-1,4,7,10,13,16-hexaoxacyclooctadeca-2,11-diene 
• 32082-45-4 trans-di(nitrobenzo)-18-crown-6 
• 61853-51-8 2,3,12,13-tetranitro-6,7,9,10,17,18,20,21-octahydro-5,8,11,16,19,22-hexaoxadibenzo[b,k]cyclooctadecene 
• 176911-77-6 2,3,13,14-Tetrakis-(2-bromo-4,5-dimethoxy-benzyl)-6,7,9,10,17,18,20,21-octahydro-5,8,11,16,19,22-hexaoxa-dibenzo[a,j]cyclooctadecene 
• 68725-69-9 2,3:11,12-bis<4',4''-n-pentylbenzo>-18-crown-6 
• 75464-37-8 2,3:11,12-bis<4',5''-n-pentylbenzo>-18-crown-6 
• 82251-58-9 ternary complex of 2,3-dichloro-5,6-dicyano-p-benzoquinone, dibenzo-18-crown-6 and t-butylammonium perchlorate 

Relevant articles and documents

Lead ion selective electrodes from dibenzo-18-crown-6 derivatives: An exploratory study

Dibenzo-18-crown-6 (DB18C6) and three of its derivatives (-COCH3, -Br, -NO2), are investigated via Density Functional Theoretical (DFT) modelling, Fourier Transform Infrared (FT-IR) and absorption spectroscopies, Differential Pulse Anodic Stripping (DPASV), Cyclic (CV) and Square Wave (SWV) voltammetries, as possible materials for preparing plasticiser free lead(II) ion selective electrodes. The spontaneous, entropy driven, interactions between lead(II) ions and DB18C6 derivatives are such that they form 1:1 complexes via coordination with the high electron density open ether cavity, except for the brominated derivative where the metal: ligand stoichiometry is 2:1 due to exo-cavity coordination via the high electron density bromine atoms. Monolayers resulting from electropolymerization of some derivatives (-H, -COCH3, -Br) and chemisorption of the -NO2 derivative, allows quantification of lead(II) ions at concentrations below 10 mg L?1 with minimal interference from other metal ions except Hg2+ and Al3+.

Crown Ether-Functionalized Polybenzoxazine for Metal Ion Adsorption

In this study, we synthesized a new crown ether-functionalized benzoxazine monomer (crown-ether BZ) in high yield and purity through reduction of the Schiff base prepared from a dibenzo[18]crown-6 diamine derivative and salicylaldehyde and subsequent reaction of the resulting o-hydroxybenzylamine species with CH2O. We used differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, and thermogravimetric analysis to examine the thermal ring opening polymerization and thermal stability of the crown-ether BZ monomer during various types of thermal treatment. DSC revealed that this crown-ether BZ monomer featured a relatively low curing temperature (210 °C; that of the typical Pa-type 3-phenyl-3,4-dihydro-2H-benzooxazine monomer: 263 °C) because the flexibility of the crown ether moiety on the main chain backbone structure catalyzed the ring opening polymerization. We also used DSC, FTIR spectroscopy, and ionic conductivity measurements to investigate the specific metal-crown ether interactions of crown-ether BZ/LiClO4 complexes. The presence of Li+ ions decreased the curing temperature significantly to 186 °C, suggesting that the metal ions functioned as an effective catalyst and promoter that accelerated the ring opening polymerization of the crown-ether BZ monomer. The ionic conductivity reached 8.3 × 10-5 S cm-1 for the crown-ether BZ/LiClO4 = 90/10 complex after thermal c? this value is higher than those of typical polymer-based systems (e.g., PEO, PCL, PMMA, and PVP) while also providing a polymer electrolyte of higher thermal stability.

Microwave-assisted synthesis of dibenzo-crown ethers

Microwave-assisted organic synthesis (MAOS) for dibenzo-substituted crown ethers is presented. Two routes were developed: (1) one-pot MAOS for symmetric dibenzo-crown ethers (DBC) and (2) a two-step MAOS via diphenol intermediates for both symmetric and asymmetric DBCs. MAOS were carried out in open or closed vessels, with or without temperature control at various microwave settings using different bases and reactants. Open vessel MAOS was limited by the volatility of reactants hence was less preferred than the closed vessel MAOS. DBC formation was highly affected by the cation size of the base, which acted as a template ion during DBCs ring closure. Closed vessel MAOS without temperature control was found most appropriate for DBC synthesis. Symmetric DBCs were conveniently obtained via one-pot MAOS whereas asymmetric DBCs were obtained from two-step MAOS via diphenol intermediates. The method was found expedient as it afforded satisfactory yields at considerably shorter reaction time than those in conventional methods.