Amino 3,5-dinitrobenzoyl

The reaction between 3,5 dinitrobenzoyl chloride and compounds containing the OH, NHj, or NH groups is very rapid, and therefore is particularly suitable for identification purposes cf. pp. 335, 338, 381). It is usual to have sodium hydroxide present during the reaction with phenols and amino-acids, but this is not necessary with alcohols if they are dry. 

Amino Aliphatic Carboxylic Acids. 3,5-Dinitrobenzoyl derivatives (p. 381), Benzoyl derivatives (p. 382), Sulphonyl derivatives (p. 382). 

However, it was not until the beginning of 1994 that a rapid (<1.5 h) total resolution of two pairs of racemic amino acid derivatives with a CPC device was published [124]. The chiral selector was A-dodecanoyl-L-proline-3,5-dimethylanilide (1) and the system of solvents used was constituted by a mixture of heptane/ethyl acetate/methanol/water (3 1 3 1). Although the amounts of sample resolved were small (2 ml of a 10 inM solution of the amino acid derivatives), this separation demonstrated the feasibility and the potential of the technique for chiral separations. Thus, a number of publications appeared subsequently. Firstly, the same chiral selector was utilized for the resolution of 1 g of ( )-A-(3,5-dinitrobenzoyl)leucine with a modified system of solvents, where the substitution of water by an acidified solution... 

Nitrobenzoyl chloride and 3,5-dinitrobenzoyl chloride were each reacted with dl-1-phenylethylamine and 4-amino-l-benzylpiperidine using a phase-transfer reaction [23]. The amines were in the aqueous phase and the acid chlorides in the organic phase. By this means, a 2 x 2 library was created in one experimental run. 

P 9] DL-l-Phenylethylamine and 4-amino-l-benzylpiperidine were dissolved in 0.1 M NaOH aqueous solution [23]. 3-Nitrobenzoyl chloride and 3,5-dinitrobenzoyl chloride were used as ethyl acetate solutions. The concentration of all reactants was set to 0.01 M. Syringe pumps served for liquid feed. The flow rate was 50 plmin and room-temperature processing was applied. No further temperature control was exerted as the reaction is only mildly exothermic. After having passed the micro reactor, the phases were settled in test-tubes and the organic phase was withdrawn for analysis. 

Figure 4.40 Dependence of yield on specific interfacial area between aqueous or organic phase. The four combinations AC-BD refer to the respective reactions between dl-1-phenyl-ethylamine (A), 4-amino-l-benzylpiperidine (B), 3-nitrobenzoyl chloride (C), and 3,5-dinitrobenzoyl chloride (D) [23],...

Pirkle type a-Burke 2 Dimethyl A-3 -dinitrobenzoyl-a-amino-2,2-dimethyl-4-pentenyl phosphonate bonded to silica [80] Regis... 

Though y-CD was found to form complexes also with PEG, the yields were too small for their characterization. Thus, Harada et al. turned to two PEG deriva-tives-bis(3,5-dinitrobenzoyl)-PEG (PEG-DNB2) and bis(2,4-dinitrophenyl-amino)-PEG (PEG-DNP2)-, which were found to complex with this CD at high yields. Using a fluorescent probe technique the resulting complexes were shown to include four ethylene glycol units in one y-CD cavity. However, these PEG derivatives formed no complex with a-CD. This is attributable to the fact that their chains are too thick to enter the slim a-CD cavity. 

An easily accessible DA CSP derived from L-A-(2-naphthyl)valine (80) was used to separate appropriately derivatized amines, amino alcohols and thiols, derivatization consisting of N-, O- and 5-acylation with 3,5-dinitrobenzoyl chloride or 3,5-dinitrophenyl... 

A comparative study was carried out of the effectiveness of three commercially available chiral columns and nonchiral derivatives of amino acids such as A-(3,5-dinitrobenzoyl) esters (119), phenylurea esters (120), hydantoins (121) and thiohydantoins (98). Although good separations were obtained, no column was universally effective294. 

S )-Ar- -Butyl-2-(phenylcarbamoyloxy)propionamide (193) was used as chiral solvating agent in the NMR determination of the enantiomer composition of the N-(3,4-dinitrobenzoyl) derivative of amino acid ethyl esters400. 

The r-donor phases (typically naphthyl-amino-acid derivatives covalently bonded to silica) require the analyte to contain a r-acceptor group such as the dinitrobenzoyl group. The dinitrobenzoyl group can easily be added to a wide range of compounds such as alcohols, amines and carboxylic acids using dinitrobenzoyl chloride, isocyanate or dinitroanaline, as already mentioned above. 

Dinitrobenzoyl-amino acids /3-CD Linear mobility ratio 42... 

When the unsaturated Y-benzoyl a-amino ester 443 was treated with MCPBA, the oxirane 444 formed first immediately underwent an intramolecular rearrangement with cleavage of the oxirane ring by attack of the amide oxygen to give a 3 1 mixture of two cis- and /ra r-isomers of 5,6-dihydro-47/-l,3-oxazine derivatives 445 and 446, the configurations of which were determined via their 0-3,5-dinitrobenzoyl derivatives (Scheme 85) <2003M69>. 

Dinitrobenzoates. The following experimental details are for glycine (aminoacetic acid) and may be easily adapted for any other amino acid. Dissolve 0-75 g. of glycine in 20 ml. of N sodium hydroxide solution and add 2 32 g. of finely powdered 3 5-dinitrobenzoyl chloride. Shake the mixture vigorously in a stoppered test-tube the acid chloride soon dissolves. Continue the shaking for 2 minutes, filter (if necessary) and acidify with dilute hydrochloric acid to Congo red. Recrystallise the derivative immediately from water or 50 per cent, alcohol. 

A commercially packed h.p.l.c. column (25 cm x 4.6 mm) of y-aminopropyl silanised silica [e.g. 5/mi Spherisorb (Regis Chemical Co.), or 7/im Zorbax (Dupont Co.), or 10 /im Lithosorb (Merck), or 5 m irregular (J. T. Baker Chemical Co.)] was sequentially treated, at a pumping rate of 2 ml/min, with the following solutions 2 ml of triethylamine in 40 ml of dry tetrahydrofuran, 2g of (R)-JV-(3,5-dinitrobenzoyl)phenylglycine in 40 ml of dry tetrahydrofuran, 20 ml of dry tetrahydrofuran, and finally 10 per cent propan-2-ol in hexane, until the base line stabilises. The chiral amino acid derivative (which is available from Aldrich Chemical Co.) becomes ionically bonded to the amino residues on the stationary phase. 

The first ionically bonded phase was presented by Pirkle it contained (/ )-3,5-dinitrobenzoyl phenylglycine [13]. The most commonly used 7t-acid moiety is the 3,5-dinitrophenyl group introduced by the reaction of 3,5-dinitrobenzoyl chloride (DNB-C1) on chiral selectors such as amino acids, amino alcohols, and amines. In addition, pentafluorobenzoyl derivatives have also been reported [14,15]. The 7r-basic phases are complimentary to the re-acidic phases. These CSPs include the presence of phenyl- or alkyl-substituted phenyl groups. Macaudiere et al. [9] designed a CSP containing both re-acidic and re-basic... 

The applications of re-acidic chiral stationary phases include the resolution of a-blockers and /1-blockers, amines, arylacetamine, alkylcarbinols, hydantoins, barbiturates, naphthols, benzodiazapines, carboxylic acids, lactams, lactones, phthaldehydes selenoids, and phosphorus compounds. Hyun et al. [16] achieved a chiral resolution of a homologous series of iV-acyl-x-(l-naphthyl )cthylaminc on AA(3,5-dinitrobenzoyl-(i )-phenylglycine and N-(3,5 - dini tr o ben zoy I)-(,S ) -1 c u c ine CSPs. The authors used hexane-2-propanol (80 20, v/v) as the mobile phase. Similarly, the scope of re-basic CSPs comprises the chiral resolution of / -blockers, amino acids, amines, diamines, amino phosphonates, naphthols, benza-diazapines, carboxylic acids, hydroxy acids, dipeptides, tripeptides, diols,... 

As in the case of other CSPs, the chiral resolution is effected by the structure of the solute. The chiral resolution of amino acids may be considered as the best example for this study. The work of Fukushima et al. [20] (i.e., the chiral resolution of amino acids) indicated the different behavior of the chiral resolution on (i8 )-/V-3,5-dinitrobcnzoyl-l -naphthylglycine CSP. Altomare etal. [142] studied the chiral resolution of a series of 3-phenyl-4-(l-adamantyl)-5-A-phcnyl-A2-1,2,4-oxadiazolines on A,Af,-(3,5-dinitrobenzoyl)-l(7 ),2( )-diaminocyclohcxanc CSP. The effect of the influence of aromatic ring substituents on enantioselectivity was studied by traditional linear free-energy-related equations and comparative molecular field analysis methods. The authors reported that an increase in retention was favored by the re-basicity and the hydrophilicity of the solutes. In... 

Other chiral molecules were also used as CMPAs. Lammerhofer and Lindner [90] resolved the enantiomers of N-derivatized amino acids (e.g., 3,5-dinitrobenzoyl,... 

Wang and Porter [92] resolved the enantiomers of oxazepam, lorazepam, and temazepam using /1-cyclodextrin as the CMPA by CEC. The authors varied separation parameters such as voltage and mobile phase. Wei et al. [93] resolved the enantiomers of phenylephrine and synephrine by varying the concentration of /1-cyclodextrin (CMPA), pH, electrolyte concentration, and temperature. Lelievre et al. [99] separated the enantiomers of chlorthalidone using hydroxypropyl /1-cyclodextrin as the CMPA. Lammerhofer and Lindner [90] resolved the enantiomers of N-derivatized amino acids (e.g., 3,5-dinitrobenzoyl, 3,5-dinitro-benzyloxycarbonyl, 2,4-dinitrophenyl, and 9-fluorenylmethoxycarbonyl amino... 

Analytical Properties Separation of 3,5-dinitrobenzoyl derivatives of amino acids 3,5-dinitroanilide derivatives of carboxylic acids Reference 19... 

As a further test of the etched open tubular approach for the analysis of optical isomers, another column was fabricated based on the selector naphthylethylamine that had been attached to porous silica by the silanization/hydrosilation method for use in HPLC [70]. As in the HPLC experiments, this column was best suited for the resolution of the optical isomers of dinitrobenzoyl methyl esters of amino acids. The best separation (a = 1.14) was obtained for the alanine derivative. In addition, the peak symmetry and efficiency for the naphthylethylamine column was significantly better than that obtained on the cyclodextrin column. However, as shown in HPLC experiments, changes in the amino acid moiety (replacing alanine with valine, etc.) often results in a loss of chiral resolution. In the case of optical isomers, the separation mechanism in HPLC and CEC modes is identical since only interaction between the solute and the bonded phase can result in resolution of the enantiomers. 

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