| Identification | More | [Name]
1,8-Bis(dimethylamino)naphtalene | [CAS]
20734-58-1 | [Synonyms]
1,8-bis(dimethylamino)naphtalene
1,8-BIS(DIMETHYLAMINO)NAPHTHALENE
LABOTEST-BB LT00453982
N1,N1,N8,N8-TETRAMETHYLNAPHTHALENE-1,8-DIAMINE
N,N,N',N'-BIS(DIMETHYLAMINO) NAPHTHALENE
N,N,N',N'-TETRAMETHYL-1,8-DIAMINONAPHTHALENE
N,N,N',N'-TETRAMETHYL-1,8-NAPHTHALENEDIAMINE
PROTON SPONGE
PROTON-SPONGE(R)
1,8-Naphthalenediamine,N,N,N’,N’-tetramethyl-
8-Naphthalenediamine,N,N,N’,N’-tetramethyl-1
tetramethyl-1,8-naphthalenediamine
N,N,N',N'-tetramethylnaphthalene-1,8-diamine
PROTON-SPONGE (1,8-BIS-(DIMETHYLAMINO)NAPHTHALENE), 99%
proton-sponge tm
1,8-BIS(DIMETHYLAMINO)NAPHTHALENE, 98+%
1,8-Bis(dimethylamino)naphthalene [for Dehydrohalogenation]
1,8-Bis(dimethylamino)naphthalene, Proton-sponge(R)
1,8-Bis(dimethylamino)naphthalene, N,N,Nμ,Nμ-Tetramethyl-1,8-naphthalenediamine
4,5-Bis(dimethylamino)naphthalene | [EINECS(EC#)]
244-001-6 | [Molecular Formula]
C14H18N2 | [MDL Number]
MFCD00003920 | [Molecular Weight]
214.31 | [MOL File]
20734-58-1.mol |
| Safety Data | Back Directory | [Hazard Codes ]
Xn,C | [Risk Statements ]
R22:Harmful if swallowed.
R36/37/38:Irritating to eyes, respiratory system and skin .
R34:Causes burns. | [Safety Statements ]
S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice .
S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) .
S36/37/39:Wear suitable protective clothing, gloves and eye/face protection . | [RIDADR ]
3259 | [WGK Germany ]
3
| [F ]
8-10-23 | [HazardClass ]
8 | [HS Code ]
29215900 |
| Hazard Information | Back Directory | [Description]
Significant attention in organic chemistry has been given to the so-called proton sponges, which are bi-center nitrogen bases that show spectacularly high basicity and very low nucleophilic character. The first member of this class of compounds 1,8-bis(dimethylamino)naphthalene or DMAN dragged attention due to its unexpectedly high basicity (pKa: DMAN 12.1; 1,8-diaminonaphthalene: 4.6) after its discovery in 1941[1]. It is prepared with an 82% yield from 1,8-diaminonaphthalene, dimethyl sulfate, and sodium hydride.
| [Chemical Properties]
1,8-Bis(dimethylamino)naphtalene is pale brownish-pink crystalline powder
| [Uses]
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. | [Uses]
Very strong base in organic synthesis and catalysis. | [Definition]
ChEBI: N1,N1,N8,N8-tetramethylnaphthalene-1,8-diamine is a member of naphthalenes. | [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. | [Mechanism of action]
A possibility of non-conventional two-step protonation of 1,8-bis(dimethylamino)naphthalene (proton sponge) is discussed. Unlike the generally accepted mechanism, involving relatively slow direct penetration of a proton into the cleft between the peri-NMe2 groups, it consists of the rapid addition of a proton to the out-inverted NMe2 group with the subsequent slower rotational transfer of the proton into the inter-nitrogen space to produce a stable chelated cation. The conclusion is that both pathways of proton sponge protonation, traditional and non-conventional, contribute in parallel with a still undefined ratio. The estimated out-basicity of the proton sponge is at least 5.5 orders of magnitude lower than the directly measured in-basicity[2]. | [Solubility in organics]
Soluble in most organic solvents, such as methanol and chloroform. | [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.] | [References]
[1] Utsab Bhattacharyya, Ralph Puchta, Renjith Thomas . “The proton sponge 1,8-bis(dimethylamino)naphthalene: The quicker-picker-upper also for s-block metal cations?” Chemical Physics Letters 777 (2021): Article 138735.
[2] Ozeryanskii, Valery A. et al. “Out-Basicity of 1,8-bis(dimethylamino)naphthalene: the experimental and theoretical challenge??.” Organic & Biomolecular Chemistry 15 (2013): 2360–2369.
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