Process Development for the Manufacture of the Antimalarial Amodiaquine Dihydrochloride Dihydrate.

A robust process for the manufacture of the active pharmaceutical ingredient (API) amodiaquine dihydrochloride dihydrate (ADQ, 3), an important antimalarial, is reported. The process consists of a three-step synthetic route that involves a Mannich reaction, substitution with 4,7-dichloroquinoline (4,7-DCQ, 5), and rehydration. Additionally, a cost-competitive process for the production of 4,7-DCQ (5) is also reported wherein 4,7-DCQ (5) was prepared in four steps from meta-chloroaniline (7). 4-Acetamido-2-(diethylaminomethyl)phenol (14), 4,7-DCQ (5), and ADQ (3) were obtained in yields of 92, 89, and 90%, respectively. Costing and process mass intensities of 4,7-DCQ and ADQ are also reported.

Dopant distribution and influence of sonication temperature on the pure red light emission of mixed oxide phosphor for solid state lighting.

In this study, europium doped yttrium gadolinium (Y1.4Gd0.5Eu0.1O3) mixed oxide phosphors were synthesized by a sonochemical method at different growth temperatures (50°C, 100°C, 150°C and 200°C) for pure red light emission applications. The compositional identification, presence of dopants and the distribution of doping materials in the crystal lattice was studied by TOF-SIMS. The formation and growth mechanisms in the sonochemical synthesis of Y1.4Gd0.5Eu0.1O3 nanophosphors are discussed in detail. Different spectral and Judd-Ofelt parameters were estimated from photoluminescence data. Optical gain and efficiency parameters were calculated with the variation of synthesis environment and an efficient synthesis method to make good red emitting phosphors for solid-state lighting and display applications were proposed.

Synthesis of Fused Polycyclic Indoles by Brønsted Acid-Catalyzed Intramolecular Alkylation of Indoles with Alcohols.

An efficient methodology for the synthesis of a series of new fused polyclyclic indoles has been developed by Brønsted acid-catalyzed intramolecular Friedel-Crafts reactions of properly designed indolyl alcohols.

The role of neutral and ionized oxygen defects in the emission of tin oxide nanocrystals for near white light application.

Tin oxide (SnO2) nanocrystals (NCs) based phosphor was synthesized by a green chemistry microwave-assisted hydrothermal method at different reactor pressures. The x-ray diffraction analysis showed that a single rutile SnO2 phase with a tetragonal lattice structure was formed. The photoluminescence emission was measured for He-Cd laser excitation at 325 nm and it showed a broad band emission from 400 to 800 nm for all the synthesized reactor pressures. The broad emission spectra were due to the creation of various oxygen and tin defects as confirmed by x-ray photoelectron spectroscopy data. The origin of the emission in the SnO2 NCs is discussed with the help of an energy band diagram. Analysis suggests that the visible emission of SnO2 NCs is due to a transition of an electron from a level close to the conduction band edge to a deeply trapped hole in the SnO2 NCs. The NCs were found to be suitable for warm near white light emission device applications.

Influence of ultrasonication times on the tunable colour emission of ZnO nanophosphors for lighting applications.

This paper reports on the sonochemical synthesis of zinc oxide (ZnO) nanophosphors (NPr) at different ultrasonication times (5 min, 30 min, 1h, 5h, 10h and 15 h) for near white light emission applications. X-ray photoelectron spectroscopy indicated that the O1s peak consists of two components. These were O1 (ZnO) and O2 (deficient oxygen; OH groups) centred at 529.7±0.3 eV and 531.1±0.3 eV, respectively. All samples showed UV and defect level emission (DLE). The DLE enhancement was due to the increase in oxygen related defects such as oxygen vacancies/interstitials. Due to the combination of near UV and DLE near white light emission in ZnO NPr was obtained. The emission could be tuned with different ultrasonic times. It was found that the ultrasonication time influenced the growth mechanism and luminescence properties of the ZnO NPr.

5-(3,4-Dimeth-oxy-benzyl-idene)-1,3-dimethyl-1,3-diazinane-2,4,6-trione.

In the title compound, C(15)H(16)N(2)O(5), the dihedral angle between 1,3-diazinane and benzene rings is only 4.27 (1)°. The essentially planar mol-ecular structure is characterized by a short intra-molecular C-H⋯O separation and by an exceptionally large bond angle of 138.25 (14)° at the bridging methine C atom. The meth-oxy groups deviate somewhat from the plane of the benzene ring, with C-C-O-C torsion angles of -15.6 (1) and 9.17 (6)°. In the crystal, mol-ecules form centrosymmetric dimers via donor-acceptor π-π inter-actions, with a centroid-centroid distance of 3.401 (1) Å.

4-(2-Bromo-phen-yl)-2-phenyl-pyrano[3,2-c]chromen-5(4H)-one.

In the title compound, C24H15BrO3, the pyran-ochromenone ring is essentially planar, while the 2-bromo-phenyl group is almost perpendicular to it [85.58 (6)°]. In the crystal, inversion dimers linked by pairs of weak C-H⋯π bonds occur; there is also a short inter-atomic contact found between the Br and carbonyl O atoms [3.016 (1) Å].

2,5-Dihexyl-thio-phene 1,1-dioxide.

In the title mol-ecule, C16H28O2S, the two n-hexyl groups are in all-trans conformations. Their C atoms are situated close to the plane of the thio-phene ring with a maximum deviation of 0.718 (6) Šfor one of the terminal methyl groups. In the crystal, a short C-H⋯O contact is observed between thio-phene 1,1-dioxide groups.

Dimethyl 2,6-dimethyl-4-phenyl-pyridine-3,5-dicarboxyl-ate.

In the title compound, C(17)H(17)NO(4), the dihedral angle between the benzene and pyridine rings is 75.51 (4)°. The benzene and pyridine rings are both approximately planar (r.m.s. deviations of 0.0040 and 0.0083 Å, respectively), indicating that the pyridine N atom is not protonated. The crystal structure is stabilized by weak inter-molecular C-H⋯O and C-H⋯N inter-actions.

Racemic tricarbon-yl[7-meth-oxy-2-(η-phen-yl)chromane]-chromium(0).

In the title compound, [Cr(C(16)H(16)O(2))(CO)(3)], the Cr(0) atom of the Cr(CO)(3) unit is coordinated to the phenyl ring of the flavan ligand in an η(6) mode, with a normal arene-to-metal distance. The Cr(CO)(3) unit exhibits a three-legged piano-stool conformation, while the dihydro-pyran ring displays a distorted envelope configuration. The phenyl ring is twisted away from the fused ring system by 25.5 (2)°. The meth-oxy group is almost coplanar with the phenyl ring [C(Me)-O-C(ar)-C(ar) torsion angle = 8.46 (2)°]. The crystal packing is stabilized by inter-molecular C-H⋯O inter-actions.

Green chemistry approaches to the regioselective synthesis of spiro heterobicyclic rings using iodine as a new and efficient catalyst under solvent-free conditions.

Iodine catalyzes the pseudo four-component reaction of an aldehyde, a urea or thiourea, and cyclic 1,3-dicarbonyl compounds under microwave irradiation in a solvent-free condition to yield various σ symmetric spiro heterobicyclic rings in excellent yields.

Synthesis of diverse indole-containing scaffolds by gold(I)-catalyzed tandem reactions of 3-propargylindoles initiated by 1,2-indole migrations: scope and computational studies.

Similar to propargylic carboxylates and sulphides, 3-propargylindoles undergo 1,2-indole migrations under cationic gold(I) catalysis. The intermediate Au-carbenoid complex may evolve through different pathways depending on the substituents at the propargylic and terminal positions of the alkyne moiety. Thus, 3-indenylindole derivatives were easily obtained through formal iso-Nazarov or Nazarov cyclizations. DFT computations support the formation of an alkylidenecyclopropane intermediate that undergoes gold-iso-Nazarov or gold-Nazarov cyclizations upon torquoselective ring opening. In addition, 3-dienylindoles could be accessed when none of the referred pathways were accessible and so the intermediate Au-carbenoid complex evolved via a 1,2-C-H insertion reaction. We have also demonstrated that the final products can be obtained in a one-pot protocol from easily available propargylic alcohols and indoles.

An efficient synthesis of novel pyrano[2,3-d]- and furopyrano[2,3-d]pyrimidines via indium-catalyzed multi-component domino reaction.

Various novel pyrano [2,3-d]pyrimidines 5 and furopyrano [2,3-d]pyrimidines 7 were synthesized in 80-99% yields via a multicomponent domino Knoevenagel/hetero-Diels-Alder reaction of 1,3-dimethyl barbituric acid with an aromatic aldehyde and ethyl vinyl ether/2,3-dihydrofuran in presence of 1 mol% of indium(III) chloride. The reaction also proceeds in aqueous media without using any catalyst, but the yield is comparatively less (65-70%).

Regiospecific one-pot synthesis of pyrimido[4,5-d]pyrimidine derivatives in the solid state under microwave irradiations.

Electron rich 6-[(dimethylamino)methylene]amino uracil 1, undergoes [4+2] cycloaddition reactions with various in situ generated glyoxylate imine and imine oxides 6 to provide novel pyrimido[4,5-d]pyrimidine derivatives of biological significance, after elimination of dimethylamine from the (1:1) cycloadducts and oxidative aromatisation. This procedure provides a convenient method for the direct synthesis of pyrimido[4,5-d]pyrimidines in excellent yields when carried out in the solid state and under microwave irradiations.