2-nitrobenzoyl Chloride Research Articles

A combined experimental and theoretical study of the synthesis of quinazolino[3,2-a][1,5]benzodiazepin-13-ones

A simple and efficient general approach to various tetracyclic 6,7-dihydroquinazolino(3,2- a)(1,5)benzodiazepin-13(5H)-ones has been demonstrated by reductive N-heterocyclization of 5- alkyl- or benzoyl-1-(2-nitrobenzoyl)-1,3,4,5-tetrahydro-2H-1,5-benzodiazepin-2-ones. These 2- nitrobenzoylamides were obtained by acylation of the starting 5-alkyl- or benzoyl-1,5- benzodiazepin-2-ones with 2-nitrobenzoyl chloride. A theoretical understanding of the features of the reductive N-heterocyclization reaction was provided by means of quantum chemical reactivity descriptors calculations.

Synthesis of 2-amino-1,4-benzodiazepin-5-ones from 2-nitrobenzoic acid and α-aminonitriles

Condensation of α-aminonitriles with 2-nitrobenzoyl chloride gives the corresponding Schiff bases, which furnish, upon reduction with Zn, the corresponding 2-amino-3,4-dihydro-5H-1,4benzodiazepin-5-ones. However, reduction of the Schiff base obtained from the condensation of 1-aminocyclohexanecarbonitrile with 2-nitrobenzaldehyde gives the methanol adduct of 2aminobenzaldehyde trimer.

Practical synthesis of potential endothelin receptor antagonists of 1,4-benzodiazepine-2,5-dione derivatives bearing substituents at the C3-, N1- and N4-positions

The expedient synthesis of various 1,4-benzodiazepine-2,5-dione compounds, particularly those having substituents at the C3-, N1- and N4-positions is achieved. The important features in these synthetic strategies include: (i) using the coupling reaction of isatoic anhydride with alpha-amino ester for direct construction of the core structure of 1,4-benzodiazepine-2,5-dione; (ii) using potassium carbonate as the base of choice for selective alkylation at the N1-site, while using lithiated 2-ethylacetanilide as the required base to furnish the N4-alkylation; and (iii) using 2-nitrobenzoyl chloride as a synthetic equivalent of anthranilic acid to facilitate the polyethylene resin-bound liquid-phase combinatorial synthesis. The prepared 1,4-benzodiazepine-2,5-dione compounds are evaluated for endothelin receptor antagonism by a functional assay that measures the inhibitory activity against the change of intramolecular calcium ion concentration induced by endothelin-1. The preliminary results indicate that 1,4-benzodiazepine-2,5-diones bearing two flanked aryl substituents at the N1- and N4-sites show better inhibitory activity than the corresponding unalkylated and N-monoalkylated compounds. A promising candidate, 1-benzyl-7-chloro-3-isopropyl-4-(3-methoxybenzyl)-1,4-benzodiazepine-2,5-dione (17b), exhibits an IC50 value in low nM range.

Effects of heating rate, temperature and iron catalysis on the thermal behaviour and decompostion of 2-nitrobenzoyl chloride

Runaway reactions arising from the decomposition of thermally unstable materials are a concern in industry due to the potentially devastating effects that they yield. Studies into the occurrence of thermal runaway incidents have shown the most likely cause to be a result of an inadequate investigation of the process prior to its operation on a large-scale. The chlorination of ortho-nitrated carboxylic acids is an industrially important reaction in the fine and agrochemical industries. The products of these reactions, ortho-nitrated acid chlorides, have been involved in runaway incidents that have resulted in violent explosions; hence, their thermal stability must be studied. Previous studies [S.D. Lever, M. Papadaki, Study of condition-dependent decomposition reactions: the thermal behaviour and decompostion of 2-nitrobenzoyl chloride, Part I, J. Hazard. Mater. 115 (2004) 91–100] showed that the decomposition of the parent molecule, 2-nitrobenzoyl chloride, is highly condition-dependent with the sample heating rate and temperature of decomposition playing a preponderant role in the course of the decomposition. Here, we present the results of studies of the decomposition of 2-nitrobenzoyl chloride, when the sample is subjected to various heating treatments, temperatures and in the presence of iron. As the temperature of decomposition was increased from 150 to 162 °C, the heat of decomposition was reduced from −215 to −90 kJ/mol. As the heat up rate applied in bringing the sample to the decomposition temperature increased, the heat of decomposition also increased. An increase in the heat up rate from 2 to 7.5 °C/min resulted in an increase in the heat of decomposition from −90 to −215 kJ/mol. The presence of iron and silver was observed to lower the heat of decomposition from −185 to −160 and −110 kJ/mol, respectively. Under most conditions investigated, the temperature at which gas flow was initiated was 147–150 °C. The presence of iron reduced this temperature to 140 °C. Decomposition was observed to take place over two stages, where the sample was heated directly from 40 °C at the required heat up rate. Where the sample was heated in stages and where calibrations had been carried out preceding decomposition, the decomposition took place in one stage alone.

Solubility and calorimetric study of the effects of gas environment on the decomposition of o-nitrobenzoyl chloride

When ortho -nitrated benzoic acids are chlorinated in xylene and acetonitrile, the product gases, HCl and SO 2 , dissolve in the solvent mixture. Previously measured solubilities [Lever, S. D., Papadaki, M. (2004a). o -Chlorination of 2-nitrobenzoic acid with thionly chloride in xylene and acetonitrile. Solubility study of hydrogen chloride and sulphur dioxide in xylene and acetonitrile, IChemE transactions part B. Process Safety and Environmental Protection . 48–60.] were compared to other published data and found to be in very good agreement. The heat of solution of SO 2 in xylene was evaluated calorimetrically and compared to the value obtained from our previous experimental work. In our previous work [Lever, S. D., Papadaki, M. (2004b). Study of condition-dependent decomposition reactions—the thermal behaviour and decomposItion of 2-nitrobenzoyl chloride part_I. Journal of Hazardous Materials . 115; pp. 91–100], it was reported that the products of the decomposition are condition dependent. The current study showed that the decomposition is extensively promoted by the presence of HCl. This has important safety implications should the process operating temperature be reduced and HCl solution in the solvent mixture be increased. If a thermal runaway began in the increased availability of HCl, an undesirable escalation of the runaway could occur.

Study of condition-dependent decomposition reactions: Part I. The thermal behaviour and decompostion of 2-nitrobenzoyl chloride

The risks associated with batch processing in the manufacture of chemicals and pharmaceuticals via highly exothermic reactions are of special interest due to the possibility of runaway reactions. o-Nitrated benzoyl chlorides are intermediates in the production of agrochemicals and are produced via the reaction of o-nitrated carboxylic acids with thionyl chloride in a solvent mixture. ortho-Nitrated acyl chlorides have exploded violently on attempted distillation on numerous occasions. An inadequate investigation of the process prior to large-scale operation is the most likely cause. Here we present preliminary results of studies on the decomposition of 2-nitrobenzoyl chloride. This study has revealed that the decomposition reaction is strongly condition dependent. The heating rate of the sample plays a preponderant role in the course of the decomposition reaction. That renders the interpretation of differential scanning calorimetry (DSC) or adiabatic calorimetry measurements, which are routinely used to assess the thermochemistry and safety of the large-scale reactions, problematic. Following this on-going study, we report here key features of the system that have been identified.

Dynamic helical chirality of an intramolecularly hydrogen-bonded bisoxazoline.

The synthesis and conformational properties of 2,6-bis-[2-((4S)-4-methyl-4,5-dihydro-1,3-oxazol-2-yl)phenyl]carbam oylpyridines, 2, have been described. Bisoxazoline 2a was prepared in five steps from 2-nitrobenzoyl chloride in an overall yield of 71%. In contrast to related structures such as 1, bisoxazoline 2a exhibits a highly biased P-type helical conformation in solution and in the solid state. In the crystal lattice, 2a further assembles into a left-handed helical superstructure aligned along the crystallographic c axis. The barrier to helical interconversion, as measured by line-shape analysis of the temperature-dependent (1)H NMR spectra of thiobenzyl derivative 2b, was determined to be quite low ((Delta)G(++) = 12.3 kcal/mol), indicating the presence of a highly dynamic helical chirality.

Polymers of 4-vinyl-2′-nitrodiphenylmethyl carboxylates capable of releasing functional acid by light

4-Vinyl-2′-nitrodiphenylmethyl esters (VI) of functional carboxylic acids, such as benzoic, trans-cinnamic, hydrocinnamic, 2,4-dichlorophenoxyacetic, 2-methyl-4-chlorophenoxyacetic, and 2,2-dichloropropanoic acids, were synthesized by Friedel-Crafts acylation of (2-bromoethyl)benzene with 2-nitrobenzoyl chloride to afford 4-(β-bromoethyl)-2′-nitrobenzophenone, followed by reduction, dehydrobromination, and esterification with the acids. The polymers obtained by homo- or copolymerizations (principally with styrene) were subjected to near-UV irradiation (> 300 nm) either in THF solutions under N 2 or in glass-sandwiched thin films to release functional acids, the extent of which depends upon various factors such as the chemical structure and the physical state of the polymer.

The Synthesis of 2-Aminobenzophenones

Methods for the preparation of 2-aminobenzophenone and its derivatives published from 1945 through 1979 are reviewed. The various synthetic schemes developed to date for 2-aminobenzophenones allow most derivatives to be prepared readily and in good yield. The review is completed by tables of mono- and di-substituted 2-aminobenzophenones. 1. Introduction 2. Syntheses from 2-Benzoylbenzoic Acids 3. Syntheses from 3-Arylindoles 4. Syntheses from 2,1-Benzisoxazoles 5. Syntheses from Nitroaryl Substrates 5.1. From 2-Nitrobenzyl Chloride 5.2. From 2-Nitrobenzoyl Chloride 5.3. From 2-Nitrobenzoic Acid 5.4. From 2-Chloronitrobenzene 6. Syntheses from Anthranilic Acids 6.1. From 2-Aminobenzonitrile 6.2. From 3,1-Benzoxazin-4-one 6.3. From Isatoic Anhydride 6.4. From Formamidine 6.5. From Arylsulfonamide 7. Syntheses from Anilines 7.1. para-Substitution 7.2. Boron Trichloride Complex 7.3. ortho-Lithiation 7.4. 2-Benzylaniline 8. Syntheses from Halobenzophenones 9. Syntheses of N-Alkyl Derivatives 10. Tables of Derivatives