Naphthalene 7-dimethylamino

Asymmetric hydrogenolysis of allylic esters with formic acid with satisfactory ee was observed[387], Geranyl methyl carbonate (594) was reduced to 570 with formic acid using l,8-bis(dimethylamino)naphthalene as a base and MOP-Phen as the best chiral ligand, achieving 85% ee. 

Cyclization of 3,3-dimethyl-2-hydroximino-4-tosyloxybutane (272) with 1,6-bis-(dimethylamino)naphthalene is reported to occur via iV-alkylation to give the 1-azetine Af-oxide (273) as an unstable oil which decomposes over a few days at room temperature (74TL4283). 

PhCH20CH2Cl, Nal, proton sponge [l,8-bis(dimethylamino)naphthalene], 84% yield. BOMBr can also be used. ... 

When the Dnseoc group is used in nucleoside synthesis, the coupling yields are determined by measuring the absorbance at 350 nm of each eluate from the Dnseoc-deprotection steps containing the 5-(dimethylamino)naphthalene-l-yl-vinyl sulfone or by measuring the fluorescence at 530 nm. ... 

A solution of potassium naphthalenide is prepared from 2.0 g (50 mmol) of potassium and 6.4 g (50 mmol) of naphthalene in 40 mL ofTHF. After 1 h at r.t. this mixture is diluted with 10 mL of diethyl ether and 10 mL of petroleum ether (bp 40-60 °C) and cooled to — 120 °C. 4.5 g (25 mmol) of ( )-l-methoxy-3-phenylthio-1-propcne arc added followed by 3.36 g (25 mmol) of chlorobis(l-dimethylamino)borane. This mixture is allowed to warm to r.t. over 3 h the solvents are removed in vacuo and the residue is carefully distilled through a 5-cm column at 10 2 Torr. The distillate, containing also naphthalene, is dissolved in 30 mL of diethyl ether and treated with 2.95 g (25 mmol) of pinacol for 3 h. The crude product is chromatographed over 30 g of basic alumina (activity 1) using petroleum ether (bp 40 -60°C) giving 9.2 g of a mixture of product and naphthalene the yield of product (89% E) is determined to be 60% by H-NMR analysis. Similarly prepared is ... 

To a flame-dried, argon-purged flask, equipped with a glass-coated jstirring bar, was added THF (10 ml) and lithium ribbon (5.8 mg atom). The mixture was cooled to between -45 and -55 C (hexan-l-ol/dry ice), and l-(dimethylamino)naphthalene (5.1 mmol) was added slowly. The Idark-green colour of the radical anion appeared within 10 min, and Iformation of LDMAN was complete after 3.5 h of rapid stirring. 

An excellent discussion on derivatization techniques has been given by Lawrence (17) including a detailed discussion on pre-column derivatization (18) and post-column derivatization (19). Probably, the more popular procedures are those that produce fluorescing derivatives to improve detector sensitivity. One of the more commonly used reagents is dansyl chloride (20), 5-dimethylamino-naphthalene-1-sulphonyl chloride (sometimes called DNS-chloride or DNS-C1). The reagent reacts with phenols and primary and secondary amines under slightly basic conditions forming sulphonate esters or sulphonamides. 

Substances 5-(Dimethylamino)-naphthalene-l-sulfonyl chloride Sodium carbonate, anhydrous Methanol Ethanol (96< 7o)... 

The amine-reactive 5-(dimethylamino)naphthalene-l-sulfonyl (dansyl) chloride 28 [80] and related fluorophores [81, 82], as well as the 5-((2 aminoethyl)amino) naphthalene-1-sulfonic acid (EDANS) 29, are included in the naphthalene fluorophore family. Derivatives of the latter, such as compound 30, exhibit a Lm.ix/ Lem 336/520 nm, molar absorptivity (e) of 6.1 x 103 M-1 cm-1, and a fluorescent quantum yield of 0.27 in water [83], The use of EDANS is particularly interesting in FRET experiments [84, 85]. Furthermore, 4-amino-3,6-disulfonylnaphthalimides (e.g., Lucifer yellow 31), associated to a longer absorption (Lmax 428 nm) [86] are suitable polar tracers [87]. 

The dansyl derivative 9-azidononyl-5-(dimethylamino)naphthalene-l-sulfonate 35 was used by Yi and collaborators [91] as an azido-fluorescent label in a tandem method of sulfonium alkylation and click chemistry for the modification of biomolecules. Fluorescent labeling of a protein was successfully carried out after simple incubation of BSA with sulfonium salt 36 followed by azido-containing fluorophore 35, at room temperature. 

Weber G, Farris FJ (1979) Synthesis and spectral properties of a hydrophobic fluorescent probe 6-propionyl-2-(dimethylamino)naphthalene. Biochemistry 18 3075-3078... 

The dimethylamino derivative 27 a was found to give no higher quantum yield in chemiluminescence than 27. This may be due to a steric hindrance of the dimethylamino group by the neighboring peri-hydrogen atom. However, 8-dimethylamino-naphthalene-2.3-dicar-boxylic acid hydrazide 97> 28 where a similar steric effect should be expected, is far more efficient than the parent compound (naphthalene 2.3-dicarboxylic hydrazide), the ratio of their quantum yields being about 40 1. 

Finally, the hydrazide 29 98> is strongly fluorescent in neutral solution (e.g. in dioxane), the fluorescence intensity amounting to about 200% of that of 7-dimethylamino-naphthalene-1.2 dicarboxylic hydrazide 30, which is one of the best chemiluminescent hydrazides 97b The 5-isomer, however, is very poor in chemiluminescence in an aqueous system (hemin-catalyzed oxidation with aqueous alkaline hydrogen peroxide), the light yield being only 1 % of that of the 7-isomer in DMSO/t-Bu0K/02 its quantum yield is slightly better but very distinctly below that of 30 98>">. It should be mentioned that in aqueous alkaline solu-... 

Carboxylic acids N-(Bromoacetyl)-A -[5- (dimethylamino)naphthalene-l -sulfonyl]piperazine 65... 

Kwakman et al. [65] described the synthesis of a new dansyl derivative for carboxylic acids. The label, N- (bromoacetyl)-A -[5-(dimethylamino)naphthalene-l-sulfonyl]-piperazine, reacted with both aliphatic and aromatic carboxylic acids in less than 30 min. Excess reagent was converted to a relatively polar compound and subsequently separated from the derivatives on a silica cartridge. A separation of carboxylic acid enantiomers was performed after labeling with either of three chiral labels and the applicability of the method was demonstrated by determinations of racemic ibuprofen in rat plasma and human urine [66], Other examples of labels used to derivatize carboxylic acids are 3-aminoperylene [67], various coumarin compounds [68], 9-anthracenemethanol [69], 6,7-dimethoxy-l-methyl-2(lH)-quinoxalinone-3-propionylcarboxylic acid hydrazide (quinoxalinone) [70], and a quinolizinocoumarin derivative termed Lumarin 4 [71],... 

Since the discovery of the exceptional basicity of l,8-bis(dimethylamino)-naphthalene (Alder et al., 1968) and its unusual kinetic behaviour (Hibbert, 1973, 1974, 1975) there has been considerable interest in the acid-base properties of hindered diaminonaphthalenes. 1,8-Bis(dimethylamino)naph-thalene (pK — 12.1 at 25°C and ionic strength 0.1 mol dm-3) (Alder et al., 1968 Hibbert, 1974 Chiang et al., 1980) is more basic than most aliphatic amines and the pAT-values of the partially methylated diamines [52] illustrate the dramatic effect of introducing the fourth methyl group (Alder et al., 1968). Reaction of protonated l,8-bis(dimethylamino)naphthalene with... 

In 1,8-bis(dimethylamino)naphthalene steric and lone pair interactions are minimised in a structure (Einspahr et al., 1973) having the amino groups twisted and displaced above and below the plane of the naphthalene ring, as in [53] in which the almost planar naphthalene ring is shown as a dashed line. In l,8-bis(dimethylamino)-2,7-dimethoxynaphthalene, steric interactions involving the methoxy substituents bring about a further distortion as in [54] (Woolf, 1980). 

A considerable amount of the strain in l,8-bis(dimethylamino)naphtha-lene is relieved by protonation and the N—H N bond length (260 pm) in the protonated amine shows that the molecule is able to adopt a conformation [55] with an intramolecular hydrogen bond (Truter and Vickery, 1972). The infra-red spectrum of protonated l,8-bis(dimethylamino)naphthalene and the chemical shift (5 19.5) of the acidic proton in the nmr spectrum confirm the presence of an intramolecular hydrogen bond (Alder et al., 1968). The magnitude of the isotope effect on the chemical shift (Altman et al., 1978) and the appearance of two Nls peaks in the photoelectron spectrum... 

---