Synthesis of octahydroquinazolinone derivatives using silica sulfuric acid as an efficient catalyst

Octahydroquinazolinone derivatives were synthesized in moderate to high yields via one-pot three component Biginelli reaction of dimedone, urea or thiourea and corresponding aromatic aldehydes in the presence of silica sulfuric acid as an efficient catalyst, in ethanol under reflux conditions. This protocol offers several advantages including good yields of products and easy experimental work-up procedure

Synthesis of some novel Schiff bases containing 1,2,4-triazole ring

4-Allyl-5-piridine-4-yl-4H-1,2,4-triazole-3-thiol was prepared under facile condition via the formation of 2-isonicotinoyl-N-allylhydrazinecarbothioamide. In addition, ethyl[(4-allyl-5-pyridine-4-yl-4H-1¸2¸4-triazole-3-yl)thio]acetate was synthesized via the reaction of 4-allyl-5-piridine-4-yl-4H-1,2,4-triazole-3-thiol with ethyl chloroacetate. 2-[(4-Allyl-5-pyridine-4-yl-4H-1,2,4-triazole-3-yl)thio]acetohydrazide obtained by using ethyl[(4-allyl-5-pyridine-4-yl-4H-1¸2¸4-triazole-3-yl)thio]acetate as a precursor by two steps, was converted to Schiff base derivatives, 6a-j. All synthesized compounds were characterized by elemental analyses, IR spectroscopy, 1H NMR and 13C NMR spectroscopy. The cis/trans conformers of E isomer were present in DMSO solution of compounds 6a-j

Synthesis of Some Benzimidazole-substituted Benzotriazoles

2-Alkylsubstituted benzimidazoles (3a–h) were prepared from the acid-catalyzed reaction of 4-methyl-1,2-phenylenediamine with corresponding carboxylic acids. Addition of these benzimidazoles to N-chloromethylbenzotriazole in the presence of sodium amide under reflux conditions gave the novel benzimidazole-substituted benzotriazoles (5a–f). IR and 1HNMR spectroscopy and elemental analysis were used for the identification of these compounds.Keywords: Phenylenediamine, benzimidazole, benzotriazol

Kinetic H/D exchange study of Co(III) coordination compounds of diazines using NMR spectroscopy

The Co(III) diazines complexes having composition (NH3) 5CoPhtz)(ClO4), (1) (Phtz = phthalazine), (NH 3)5CoPydz)(ClO4)3 (2) (Pydz = pyradazine), (NH3)5Co(3-Me-Pydz)(ClO4) 3 (3) (3-Me-Pydz = 3-methyl pyradazine) and (NH3) 5Co(3-MePhtz)(ClO4)3 (4) (3-MePhtz = 3-methyl phthalazine), (NH3)5Co(ImH)(ClO4), (5) (ImH = imidazole), (NH3)5Co(NMeIm)(ClO4) 3 (6) (N-MeIm = N-methylimidazole) undergo OD--catalyzed H/D exchange at the ortho position of the coordinated site. Rate constants for H/D exchange of these complexes at 25°C or 60°C were obtained in alkaline D2O solution using NMR spectroscopy. Reaction rate for (NH3)5CoPhtz)(ClO4)3, (NH 3)5CoPydz)(ClO4)3, (NH 3)5Co(3-MePydz)(ClO4)3 and (NH3)5Co(3-MePhtz)(ClO4)3 at 25°C are faster compared to (NH3)5Co(ImH)(ClO 4)3, (NH3)5Co(N-MeIm)(ClO 4)3 (7). However (NH3) 5CoImCo(NH3)5Br5 complex does not H/D exchange at 60°C even in strong alkaline D2O solution

One-pot synthesis of tetrahydropyrimidines catalyzed by zeolite

A simple one-pot synthesis of various tetrahydro pyrimidines in the presence of NaY zeolite, as an efficient catalyst, is reported. The multicomponent reaction was carried out by a three-component coupling of 1,3-diketone, aldehyde and urea/thiourea in the presence of the catalyst to give 1(a-k). The catalyst could be reused several times. Further reaction of these pyrimidines with phosphorus oxychloride gave corresponding N-formylated compounds

N 2-(4-Chloro­benzyl­idene)-4-nitro­benzene-1,2-diamine

In the title compound, C13H10ClN3O2, the dihedral angle between the two benzene rings is 3.61 (6)°. In the crystal structure, mol­ecules are linked by weak inter­molecular C—H⋯O hydrogen bonds, forming layers parallel to the bc plane. Short inter­molecular Cl⋯Cl contacts [3.491 (1) Å] are also observed

(E)-1-(4-Chloro­benzyl­idene)thio­semi­carbazide

In the crystal of the title compound, C8H8ClN3S, mol­ecules are connected by N—H⋯S hydrogen bonds into strips parallel to the (112) planes and running along [10]. One of the amino H atoms is not involved in a classical hydrogen bond. In addition, there is a rather short inter­molecular Cl⋯S distance of 3.3814 (5) Å

4-Bromo-N-phenyl­benzamide

The mol­ecule of the title benzamide derivative, C13H10BrNO, is twisted with the dihedral angle between the phenyl and 4-bromo­phenyl rings being 58.63 (9)°. The central N—C=O plane makes dihedral angles of 30.2 (2) and 29.2 (2)° with the phenyl and 4-bromo­phenyl rings, respectively. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds into chains along [100]. C—H⋯π contacts combine with the N—H⋯O hydrogen bonds, to form a three-dimensional network

Deep Eutectic Solvents: The Organic Reaction Medium of the Century

This microreview summarizes the use of deep eutectic solvents (DESs) and related melts in organic synthesis. Solvents of this type combine the great advantages of other proposed environmentally benign alternative solvents, such as low toxicity, high availability, low inflammability, high recyclability, low volatility, and low price, avoiding many disadvantages of the more modern media. The fact that many of the components of these mixtures come directly from nature assures their biodegradability and renewability. The classification and distribution of the reactions into different sections in this microreview, as well as the emphasis paid to their scope, easily allow a general reader to understand the actual state of the art and the great opportunities opened, not only for academic purposes but also for industry.This work was supported by the University of Alicante, Spain (VIGROB-173 and UAUSTI13-09)