20734-58-1

Basic information

• Product Name: 1,8-Bis(dimethylamino)naphtalene
• Synonyms: N1,N1,N8,N8-TETRAMETHYLNAPHTHALENE-1,8-DIAMINE;N,N,N',N'-TETRAMETHYL-1,8-DIAMINONAPHTHALENE;N,N,N',N'-TETRAMETHYL-1,8-NAPHTHALENEDIAMINE;N,N,N',N'-BIS(DIMETHYLAMINO) NAPHTHALENE;PROTON SPONGE;PROTON-SPONGE(R);1,8-Naphthalenediamine,N,N,N’,N’-tetramethyl-;8-Naphthalenediamine,N,N,N’,N’-tetramethyl-1
• CAS NO: 20734-58-1
• Molecular Formula: C₁₄H₁₈N₂
• Molecular Weight: 214.31
• EINECS: 244-001-6
• Product Categories: Amines and Anilines
• Mol File: 20734-58-1.mol
• Article Data: 11

Chemical Properties

• Melting Point: 49-51 °C(lit.)
• Boiling Point: 144-145°C (3.7505 mmHg)
• Flash Point: >230 °F
• Appearance: Pale brownish-pink/Crystalline Powder
• Density: 1.12
• Storage Temp.: 2-8°C
• Solubility: Soluble in organic solvents.
• PKA: 12.1(at 25℃)
• Water Solubility: insoluble
• Sensitive: Light Sensitive
• Merck: 14,3388
• BRN: 396782
• CAS DataBase Reference: 1,8-Bis(dimethylamino)naphtalene(CAS DataBase Reference)
• NIST Chemistry Reference: 1,8-Bis(dimethylamino)naphtalene(20734-58-1)
• EPA Substance Registry System: 1,8-Bis(dimethylamino)naphtalene(20734-58-1)

Safety Data

• Hazard Codes: Xn,C
• Statements: 22-36/37/38-34
• Safety Statements: 26-45-36/37/39
• RIDADR: 3259
• WGK Germany: 3
• F: 8-10-23
• HazardClass: 8
• Hazardous Substances Data: 20734-58-1(Hazardous Substances Data)

Usage

Chemical Properties

1,8-Bis(dimethylamino)naphtalene is pale brownish-pink crystalline powder

Uses

Different sources of media describe the Uses of 20734-58-1 differently. You can refer to the following data:
1. 1,8-Bis(dimethylamino)naphthalene, also referred to as protone sponge, is a lipophilic proton trapping agent. 1,8-Bis(dimethylamino)naphthalene is used in the matrix for mass spectroscopy analysis of lipids and fatty acids.
2. Very strong base in organic synthesis and catalysis.
3. Very strong base with weak nucleophilic character due to steric effects.

General Description

Proton-sponge is also referred as 1,8-dimethylamino naphthalene. It is very strong base with weak nucleophilic character due to steric effects. It also participates in the reactions between arachno-6,9-C2B8H14 and selected acyl chlorides. It has been tested as an effective H+ scavenger.

Purification Methods

It is prepared by methylating 1,8-diaminonaphthalene, and likely impurities are methylated products. The tetramethyl compound is a stronger base than the unmethylated, di and trimethylated derivatives. The pKa values are: 1,8-(NH2)2 = 4.61, 1,8-(NHMe)2 = 5.61, 1-NHMe-8-NHMe2 = 6.43 and 1,8-(NMe2)2 = 12.34. The mixture is then treated with H2O at pH 8 (where all but the required base are protonated) and extracted with Et2O or CHCl3. The dried extract (K2CO3) yields the tetramethyldiamine on evaporation which can be distilled. It is a strong base with weak nucleophilic properties, e.g. it could not be alkylated by refluxing with EtI in MeCN for 4 days; and on treatment with methyl fluorosulfonate only the fluorosulfonate salt of the base is obtained. [NMR: Adler et al. J Chem Soc, Chem Commun 723 1968, Brown & Letang J Am Chem Soc 63 358 1941, Brzezinski et al. J Chem Soc Perkin Trans 2 857 1991.] Alternatively, crystallise proton sponge from EtOH and dry it in a vacuum oven. Store it in the dark in a CO2-free atmosphere. [Benoit et al. Can J Chem 65 996 1987, Beilstein 13 IV 344.]

Upstream product

• 109-72-8 n-butyllithium 
• 1233939-19-9 2-lithium-1,8-bis(dimethylamino)naphthalene 
• 68-12-2 N,N-dimethyl-formamide 
• 407-25-0 trifluoroacetic anhydride 
• 206761-13-9 {1,8-bis(dimethylamino)naphthalene-2-yl} bromide 
• 37471-00-4 1,3-dimethyl-2,3-dihydro-1H-perimidine 
• 64482-94-6 2,3-dihydro-1,2,2,3-tetramethyl-1H-perimidine 
• 74-88-4 methyl iodide 
• 479-27-6 naphthalene-1,8-diamine 
• 53133-89-4 1,1,3-Trimethyl-2,3-dihydroperimidinium iodide 
• 69055-49-8 protonated 1,8-bis(dimethylaamino)naphthalene 
• 88580-00-1 1,8-bis(dimethylamino)naphthalene hydroiodide 
• 77-78-1 dimethyl sulfate 

Downstream Products

• 99808-93-2 N¹,N¹,N⁸,N⁸-Tetramethyl-4-(5-nitro-7-aci-nitro-3-oxy-4,7-dihydro-benzo[1,2,5]oxadiazol-4-yl)-naphthalene-1,8-diamine 
• 263769-36-4 (+)-4β-(4-Chlorophenyl)-3α-n-propylpiperidine 
• 258827-05-3 (-)-Methyl 4β-(4-chlorophenyl)-piperidine-3β-carboxylate 
• 2273-45-2 dimethyltin oxide 
• 102525-11-1 (η⁵-indenyl)(η⁴-1,5-cyclooctadiene)iridium(I) 
• 156450-60-1 N-[[3-(octadecyloxy)-5-(tricyclo[3.3.1.1/3,7/]dec-1-ylcarbonyl)oxy]phenyl]glycine phenylmethyl ester 
• 156449-77-3 N-[(3-carbamoyl)-5-(octadecyloxy)phenyl]-N-[2-oxo-2-(phenylmethoxy)ethyl]glycine phenylmethyl ester 

Relevant articles and documents

Fractionation Factors for the Aqueous Hydroxide Ion and Solvent Isotope Effects on the Ionisation of 1,8-Bis(dimethylamino)naphthalene (Proton Sponge)

Isotopic fractionation factors φa and φb for the hydroxy hydrogen and hydrogen bonded water hydrogens of the solvated hydroxide ion are important in controlling solvent isotop effects upon reactions involving the hydroxide ion, and were required for a vibrational analysis of the solvated ion.The product φaφb3=0.434 is accurately available from e.m.f. measurements corrected for free energies of ion transfer between H2O and D2O, but separation of φa and φb, which requires measurements in H2O-D2O mixtures is known to be subject to considerable uncertainty.Thus careful measurements with 1,8-bis(dimethylamino)naphthalene gave KD2O/KH2O=0.420 (+/-) 0.006 for the ratio of basic ionisation constants in H2O and D2O and φp=0.901 (+/-) 0.014 for the fractionation factor of the protonated base, but measurements in 1:1 H2O-D2O gave an ionisation constant too small to be consistent with any reasonable fractionation factor model for the hydroxide ion.Alternative methods of dissecting φa and φb, from measurements of isotope separation factors between hydroxide solution water vapour and autoprotolysis constants of H2O-D2O mixtures, are critically reviewed and optimum values are assessed.The results are shown to be sensitive to experimental error and to medium effects but not to departures from the Rule of the Geometric Mean.

Base-promoted transformation of 2-C(O)R-1,8-bis(dimethylamino)naphthalenes into benzo[g]indole derivatives

1,8-Bis(dimethylamino)naphthalenes bearing 2-positioned trifluoroacetyl or ethoxycarbonyl group on treatment with 2-lithio-1,8-bis-dimethylamino)naphthalene undergo base-promoted transformation into benzo[g]indole derivatives in small to moderate yield, representing previously unknown mode of the pyrrole ring closure which proceeds via deprotonation of the NMe group.

Ring lithiation of 1,8-bis(dimethylamino)naphthalene: Another side of the 'proton sponge coin'

It has been found that 1,8-bis(dimethylamino)naphthalene (DMAN), unlike N,N-dimethylaniline, undergoes ring metallation in the n-BuLi-TMEDA-Et2O system with a low selectivity and in poor total yields. The situation is significantly improved in the t-BuLi-TMEDA-n-hexane system when 3- and 4-lithium derivatives become the only reaction products obtained in good yields. The formation of 3-Li-DMAN is especially desired since no method of direct meta-functionalization of DMAN is known to date. The relative stability and structure of DMAN lithium derivatives have been examined with the help of X-ray and multinuclear NMR measurements as well as DFT calculations.

peri-naphthalenediamines: XXXIV. 1,4,5,8-Tetrakis(dimethylamino)naphthalene: Alternative approaches to synthesis

New methods were proposed for synthesizing 1,4,5,8-tetrakis(dimethylamino)naphthalene with an overall yield of 4 to 12% to replace the known procedure ensuring an overall yield of 2%. Catalytic hydrogenation was shown to be inapplicable for preparation of polyaminonaphthalenes from nitro compounds having 3 or 4 nitro gruops in the α-positions. Nucleophilic amination of 1,5-dinitronaphthalene in the system NH2OH/NaOH/MeOH yields 1-amino-4-nitronaphthalene. The nitration of 1,5-bis(p-tolylsulfonylamino)-naphthalene leads to formation of 2,6-dinitro rather than 4,8-dinitro derivative, as it was believed formerly. This was confirmed by transformation of the latter into 1,2,5,6-tetrakis(dimethylamino)naphthalene. 3-Nitro, 2,6-dinitro, 2,6-diamino, and 2,4,6,8-tetranitro derivatives of 1,5-bis(dimethylamino)naphthalene, nitro and amino derivatives of 1,4,5-tris(dimethylamino)naphthalene, and 4,5-diamino-1,8-bis(methylamino)naphthalene were synthesized. By treatment with perchloric acid 1,4,5,8-tetrakis(dimethylamino)naphthalene was oxidized to 2,3-dihydroperimidinium salt.