N-(aminophenyl)oxamic acids and esters as potent, orally active antiallergy agents

Visible light-mediated photocatalytic oxidative cleavage of activated alkynes via hydroamination: a direct approach to oxamates

The direct oxidative cleavage of activated alkynes via hydroamination has been described using organic photocatalyst under visible-light irradiation at room temperature. In this reaction, the single electron oxidation of an in situ formed enamine followed by radical coupling with an oxidant finally delivers the oxamate. The key features of this photocatalytic reaction are the mild reaction conditions, metal-free organic dye as a photocatalyst, and TBHP playing a dual role as “O” source and for the regeneration of the photocatalyst.

The direct oxidative cleavage of activated alkynes via hydroamination has been described using organic photocatalyst under visible-light irradiation at room temperature.

Pd/C-catalyzed synthesis of oxamates by oxidative cross double carbonylation of alcohols and tertiary amines through C–N bond cleavage

Palladium-catalyzed oxidative cross double carbonylation reaction between tertiary amines and alcohols using oxidant O₂ and KI as the additive affords oxamates. Oxamate are as a intermediate in biological active compound and glycol synthesis.

Copper-Catalyzed Selective N-Vinylation of 3-(Hydroxyimino)indolin-2-ones with Alkenyl Boronic Acids: Synthesis of N-Vinyl Nitrones and Spirooxindoles

A copper-catalyzed selective cross-coupling reaction of 3-(hydroxyimino)indolin-2-ones with alkenyl boronic acids to access (E)-N-vinyl oxindole nitrones has been achieved under mild conditions. The studies showed that catalytic copper salt selectively gave mono N-vinylation products, while 2.0 equiv of copper salt provided double N-vinylation products. The control experiments revealed that the carbonyl group in 3-(hydroxyimino)indolin-2-one played important roles on N-vinylation. Furthermore, the prepared N-vinyl oxindole nitrones could be converted to spirooxindoles in good yields under thermal conditions.

Crystal structure of 2-(bis(4-methoxyphenyl)amino)-2-oxoacetic acid, C16H15NO5

C16H15NO5, monoclinic, P21/n (no. 14), a = 6.7689(5) Å, b = 45.219(3) Å, c = 10.1102(6) Å, β = 101.360(7)°, V = 3033.9(4) Å3, T = 298(2) K.

Structure-activity relationships of 3,4-dihydro-1H-quinazolin-2-one derivatives as potential CDK5 inhibitors

Cyclin-dependent kinase 5 (CDK5) is a serine/threonine kinase that plays a critical role in the early development of the nervous system. Deregulation of CDK5 is believed to contribute to the abnormal phosphorylation of various cellular substrates associated with neurodegenerative disorders such as Alzheimer's disease, amyotrophic lateral sclerosis, and ischemic stroke. Acyclic urea 3 was identified as a potent CDK5 inhibitor and co-crystallographic data of urea 3/CDK2 enzyme were used to design a novel series of 3,4-dihydroquinazolin-2(1H)-ones as CDK5 inhibitors. In this investigation we present our synthetic studies toward this series of compounds and discuss their biological relevance as CDK5 inhibitors.

Structure-activity relationship of triazafluorenone derivatives as potent and selective mGluR1 antagonists

SAR (structure-activity relationship) studies of triazafluorenone derivatives as potent mGluR1 antagonists are described. The triazafluorenone derivatives are non-amino acid derivatives and noncompetitive mGluR1 antagonists that bind at a putative allosteric recognition site located within the seven-transmembrane domain of the receptor. These triazafluorenone derivatives are potent, selective, and systemically active mGluR1 antagonists. Compound 1n, for example, was a very potent mGluR1 antagonist (IC50 = 3 nM) and demonstrated full efficacy in various in vivo animal pain models.

Pyrrolo[1,2-a][1,4]benzodiazepine: a novel class of non-azole anti-dermatophyte anti-fungal agents

Broad screening revealed compound 1a to be a novel anti-fungal agent with high specificity towards dermatophytes. The anti-fungal structure-activity relationship of this novel class of 5,6-dihydro-4H-pyrrolo[1,2-a][1,4]benzodiazepines is described together with its mode of action that appeared to be the inhibition of squalene epoxidase. Preliminary in vivo results of the most active compounds are also reported.

Design and Synthesis of New Templates Derived from Pyrrolopyrimidine as Selective Multidrug-Resistance-Associated Protein Inhibitors in Multidrug Resistance

In our continued effort to identify selective MRP1 modulators, we have developed two novel templates, 3 and 4, through rational drug design by identifying the key pharmacophore interaction at the 7-position of the pyrrolopyrimidine template 1. Further synthesis and SAR work on these novel templates gave a number of potent MRP1 modulators with great selectivity against Pgp. Additional studies to reduce the CYP3A4 inhibition are also reported. Several compounds of these classes were subjected to in vivo xenograft studies and in vivo efficacies were demonstrated.

Velnacrine thiaanalogues as potential agents for treating Alzheimer's disease

The only therapeutic drugs for combating dementia disease are acetylcholine esterase inhibitors (AChEI). However, the use of tacrine, the first AChEI to be launched as an Alzheimer's disease (AD) drug, has been limited by serious side effects. Therefore, efforts to search for more potent and selective inhibitors of AChE still remain highly significant in the therapeutic treatment of AD. In this work we modified the cyclohexyl ring of velnacrine, a less toxic analogue of tacrine, by synthesizing a series of thiopyranoquinolines in which the C-3 methylene unit was replaced by a sulphur atom. The anti-AChE data show that the activity was maintained with the bioisosteric substitution carried out. The introduction of a chlorine atom at different positions of the aromatic ring resulted in an array of different activities. In an attempt to understand the different behaviours displayed by the chlorine-substituted derivatives, a molecular docking study was performed.

Novel antiallergic and antiinflammatory agents. Part I: Synthesis and pharmacology of glycolic amide derivatives

A series of mono-glycoloylamino derivatives was synthesized by treatment of the corresponding aromatic monoamine derivatives with glycoloyl chloride derivatives in pyridine or dichloromethane, in the presence of a base such as triethylamine or pyridine. Hydrolysis of acetoxy compounds in aqueous ammonia and methanol solution produced hydroxy derivatives with ease. These compounds were tested in the rat PCA (passive cutaneous anaphylaxis) assay by oral administration. Thiazole and thiadiazole derivatives showed moderate inhibition in this assay. In contrast, benzothiazole and benzonitrile derivatives exhibited marked inhibition. In particular, compound 5t also showed marked inhibition of eosinophil adhesion to TNF (tumor necrosis factor) -alpha-treated HUVEC (human umbilical vein endothelial cells) in the range of 10(-8)-10(-5) M.