A note on the Fourier coefficients of half-integral weight modular forms

In this note, we show that the algebraicity of the Fourier coefficients of half-integral weight modular forms can be determined by checking the algebraicity of the first few of them. We also give a necessary and sufficient condition for a half-integral weight modular form to be in Kohnen’s +-subspace by considering only finitely many terms.     

Improved Process for the Preparation of Tamsulosin Hydrochloride

Ellman's sulfinamide reagent is used in asymmetric synthesis of Tamsulosin hydrochloride. The enantiomeric ratio achieved is 87:13. The crystallization of the same with dibenzoyl tartarate afforded the product 2 with >99.5% ee.     

Cyanosilylation of Aldehydes and Ketones Catalyzed by Nanocrystalline Magnesium Oxide

Abstract

Cyanosilylation of various aldehydes and ketones with TMSCN proceeded smoothly under mild conditions to give the corresponding cyanohydrin trimethylsilyl ethers in the presence of nanocrystalline magnesium oxide. The cyanohydrin trimethylsilyl ethers of aldehydes produced cyanohydrins in good to high yields on treatment with 2 N HCl. ²⁹Si NMR spectral evidence proved that the reaction proceeds through the hypervalent silicate species by coordination to O^2?/O^? (Lewis basic site) of nanocrystalline magnesium oxide.     

Synthesis of 2-Indolyl-1-nitroalkane Derivatives Using Nanocrystalline Titanium(IV) Oxide

The catalytic Friedel–Crafts alkylation of indoles with nitroalkenes to furnish 2-indolyl-1-nitroalkane derivatives at room temperature with moderate to excellent yields is reported using nanocrystalline titanium(IV) oxide (nano-TiO₂) catalyst. In all cases, a single regioisomer was obtained. After completion of the reaction, the catalyst was recovered by centrifugation and activated under a nitrogen flow for 1 h at 250°C for further reuse. The nano-TiO₂ can be reused for four cycles with a slight decrease of activity under the same reaction conditions.     

Convenient and Efficient Synthesis of Some Novel Fused Thieno Pyrimidines Using Gewald's Reaction

Abstract

Several functionalized thienopyrimidines were synthesized by a facile synthetic method, which includes Gewald's reaction, and were characterized by spectral and analytical data. These functionalized thienopyrimidines were converted to various new chemical entities of biological importance, such as 2-piperazinymethyl thienopyrimidines (6, 8), 4-dimethylaminoethoxy thienopyrimidines (11), and 3-dimethylaminoethyl thienopyrimidines (12). All the compounds thus synthesized were screened for their invitro biological activities. Some of the compounds displayed promising serotonin 5-HT₆ receptor antagonist activities.

Synthesis of N-(Tert-butoxycarbonyl)-3-(4-thiazoIyl)-L-alanine

Efficient syntheses of N-(tert-butoxycarbonyl)-3-(4-thiazolyl)-L-alanine (11) are described.     

Selective Esterification of Aliphatic Carboxylic Acids in the Presence of Aromatic Carboxylic Acids Over Monoammonium Salt of 12‐Tungstophosphoric Acid

Monoammonium salt of 12‐tungstophosphoric acid [(NH₄)H₂PW₁₂O₄₀] was found to be a practical and useful heterogeneous catalyst for an efficient and selective esterification of aliphatic carboxylic acids with alcohols in the presence of aromatic carboxylic acids. The heteropoly acid–based heterogeneous catalyst has the advantages of a simple workup procedure, water insolubility, and good activity.     

Divergent Enantioselective Total Synthesis of Siphonarienal,Siphonarienone, and Pectinatone

A divergent synthesis of siphonarienal, siphonarienone, and pectinatone has been achieved from a common precursor 4 , which was synthesized by using an enzymatic desymmetrization approach. The major key steps involved were Grignard reaction, Wittig reaction, Evans' asymmetric alkylation, and base‐catalyzed cyclization.     

Thermal, UV, FTIR, and XRD studies of urinary stones

Various crystals are seen in human urine. Oxalate, Phosphate, Uric acid, and Urate crystals are generally seen in urinary calculi. Calcium stones are most common, comprising 75 % of all urinary calculi. They may be pure calcium oxalate or calcium phosphate or a mixture of both. Many stones are not homogeneous. Low calcium intake increases the intestinal absorption of calcium, thus decreasing the amount of calcium available in the intestinal tract to form insoluble complexes with Oxalate. Consequently, a higher amount of oxalate is available for intestinal absorption and as a result, urinary oxalate excretion increases. Mineral water consumption did not reduce urinary oxalate excretion. High urinary excretion and concentration of magnesium decrease both the nucleation and growth rates of calcium oxalate crystals in urine, because of the higher solubility of magnesium oxalate compared with calcium oxalate. Analytical results show calcium oxalate to be one of the major inorganic components of renal stones and found to be present in almost all kidney and bladder stones. About 39.5 % of the total composition of the calculi is found to contain purely calcium oxalate and also hydroxyl apatite. The ten samples are a mixture of calcium oxalate and phosphate stones. Four samples are calcium oxalate as major composition and the remaining are calcium phosphate as major composition. These kidney stones are taken photographically and size of the stone are measured using optical microscopy. These qualitative analyses are also confirmed by UV, FTIR, DSC, and XRD analysis.     

A facile strategy for the one pot multicomponent synthesis of spiro dihydropyridines from amines and activated alkynes

An efficient preparation of a series of spiro dihydropyridines via one pot four-component reactions of mono/di/tri-ketones, malononitrile, primary amines, and acetylenic esters is reported. The reaction is atom-efficient, high yielding, and follows a simple experimental procedure.