Method and compositions for treating a patient having a neurological disease or disorder, such as stroke, head trauma, spinal cord injury, spinal cord ischemia, ischemia- or hypoxia-induced nerve cell damage, epilepsy, anxiety, neuropsychiatric or cognitive deficits due to ischemia or hypoxia such as those that frequently occur as a consequence of cardiac surgery under cardiopulmonary bypass, or neurodegenerative diseases such as Alzheimer's Disease, Huntington's Disease, Parkinson's Disease, or amyotrophic lateral sclerosis (ALS).

Compounds active at a novel site on receptor-operated calcium channels useful for treatment of neurological disorders and diseases

2.24 – Pyrans and Fused Pyrans: (iii) Synthesis and Applications

We report a novel Lewis acid catalysed tandem reaction of isocyanides, chromone 3-carboxylic acid and nucleophiles. An experimentally very simple procedure, involving the use of microwave irradiation in the presence of a Lewis acid catalyst, affords a representative collection of chromone-2-carboxamides and chromone-2-carboxamido-3-esters in high yields, in just a few minutes. Such an unprecedented strategy is formally equivalent to a conjugate addition of isocyanides to Michael acceptors.

Conjugate addition of isocyanides to chromone 3-carboxylic acid: an efficient one-pot synthesis of chroman-4-one 2-carboxamides

The second chapter of this book provides information about all category of six membered ring system with N and/or O and /or sulfur atom, and their benzo derivatives. These six membered heterocycles and their benzo derivatives are not only present in drugs, vitamins, natural products, biomolecules, exhibiting antitumor, anti-inflammatory, anti-fungal, anti-bacterial, anti-depressant, anti-HIV anti-microbial, anti-malarial and anti-diabetic activities but they are also the key structural unit of pharmaceutical drugs and agrochemicals available in the market. Thus, each unit of this chapter gives due emphasis on the importance of a particular six membered heterocycle or its derivative under study in natural product, medicine and material. Each unit of the chapter also provides information about the structure of the individual heterocycle especially in terms of X-ray and spectroscopic data. After that synthesis, chemical reactivity and application of these heterocycles have been discussed. It is worth mentioning that wherever necessary, possible mechanism of the some typical reactions as well as name reactions have been discussed.

Six-Membered Heterocycles

The reaction of ethyl chromone-2-carboxylates with 1,2-diaminobenzene

The fine structures of the products of the cleavage of the heterorings of chromones and 4-pyrones by ammonia and primary and secondary amines, i.e., 2-β-aminoacrylylphenols (I) and di(β-aminovinyl) ketones (II), were studied by means of IR and PMR spectra, and it was established that I and II, which contain amino groups with a hydrogen atom attached to the nitrogen, exist in the cis form with double intramolecular (chelate) bonding between one carbonyl and two proton-containing groups.

Studies of pyrans and related compounds: XLIV. Structures of the products of the opening of the pyrone ring of 4-pyrones by amines

4-Chlorobenzopyrylium and 4-chloroflavylium salts have been synthesized, and some reactions of benzopyrylium cations of this type have been studied.

Synthesis of some 4-chlorobenzopyrylium salts and their reactions

Research into analogs of pyran and related compounds: XXIX. The reaction of 4,4-dichlorochromenes (4,4-dichloro-4H-1-benzopyrans) with derivatives of cyanoacetic acid

Reaction of 4, 4-dichloroflavine (I) with sulfurylchloride affords 2, 3, 3, 4, 4-pentachloroflavan (II). Hydrolysis of II gives 2-hydroxy-3, 3-dichloro-4-flavanone (III), while alcoholysis with aqueous alcohols yields 2-alkoxy-3,3-dichloro-4-flavanones (IVa, b). Treatment of III with SOCl2 gives 2,3,3-trlchloro-4-flavanone (V), which with caustic alkali or sodium ethoxide is converted into o-(1-phenyl-2, 2-dichlorovinyloxy)benzoic acid (VIc) or its ethyl ester (VIb), respectively.

Pyrans, their analogs, and related compounds

The effect of amines (benzylamine, N,N-dimethylethylenediamine, and ethylenediamine) on the tert-butyl ester (I) and tert-butyl amide (II) of chromone-2-carboxylic acid was studied. In contrast to the sterically unhindered derivatives of chromone-2-carboxylic acid, I and II do not undergo amidation or transamidation by reaction with the amines but are converted directly to pyran-ring-opening products. In the case of ethylenediamine, further intramolecular cyclization also occurs to form 5-(o-hydroxyphenyl)-7-carboxy-1,4-diaza-4,6-cycloheptadiene derivatives (VII and IX).

I. D. Tsvetkova

Papers

Studies of pyrans and related compounds: XLIV. Structures of the products of the opening of the pyrone ring of 4-pyrones by amines

Synthesis of some 4-chlorobenzopyrylium salts and their reactions

Research into analogs of pyran and related compounds: XXIX. The reaction of 4,4-dichlorochromenes (4,4-dichloro-4H-1-benzopyrans) with derivatives of cyanoacetic acid

Pyrans, their analogs, and related compounds

Pyran, its analogs, and related compounds