Design, Synthesis and Biological Evaluation of Novel Promising Analgesics.

Introduction: An analysis of the literature on the painkillers long used in traditional medicine, which are isolated from plant materials, has shown that many of them are alkylamides of various carboxylic acids. This fact served as the basis for the study of a large group of N-alkyl-4- methyl-2,2-dioxo-1H-2λ,1-benzothiazine-3-carboxamides as potential new analgesics. The objects of the study were synthesized in the traditional way involving the initial conversion of 4-methyl- 2,2-dioxo-1H-2λ,1- benzothiazine-3-carboxylic acid to imidazolide, in which imidazolide was used as an acylating agent.

Polymorphic modifications of a 1H-pyrrolo[3,2,1-ij]quinoline-5-carboxamide possessing strong diuretic properties.

6-Hydroxy-N-(4-methoxyphenyl)-4-oxo-2,4-dihydro-1H-pyrrolo[3,2,1-ij]quinoline-5-carboxamide, CHNO, possesses strong diuretic properties and can be used as a new hypertension remedy. Two polymorphic modifications of this compound have been found, namely the triclinic polymorph (space group P-1), with one molecule in the asymmetric unit, and the monoclinic polymorph (space group P2/n), with two molecules in asymmetric unit. An analysis of the pairwise interaction energies between the molecules in the crystal phase revealed differences in the crystal packing.

Mol-ecular and crystal structure of methyl 4-methyl-2,2-dioxo-1-2λ,1-benzo-thia-zine-3-carboxyl-ate.

The title compound, CHNOS, possesses weak analgesic properties and is a source compound for the synthesis of highly active analgesic and anti-inflammatory compounds. The benzo-thia-zine ring adopts a conformation intermediate between twist-boat and sofa. The ester substituent is turned towards the endocyclic double bond because of steric repulsion.

The Study of the Structure-Diuretic Activity Relationship in a Series of New -(Arylalkyl)-6-hydroxy-2-methyl-4-oxo-2,4-dihydro-1-pyrrolo-[3,2,1-]quinoline-5-carboxamides.

In accordance with the principles of "me-too" technique, the preparative method for obtaining has been proposed, and the synthesis of a large series of new -(arylalkyl)-6-hydroxy-2-methyl-4-oxo-2,4-dihydro-1-pyrrolo[3,2,1-]quinoline-5-carboxamides as structurally close analogs of tricyclic pyrrolo- and pyridoquinoline diuretics has been carried out. All target compounds were obtained with high yields and purity by amidation of ethyl ester of the corresponding 2-methyl-pyrroloquinoline-5-carboxylic acid with arylalkylamines in boiling ethanol. Their structure was confirmed by the data of elemental analysis, nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry and polarimetry.

N-Aryl-7-hydroxy-5-oxo-2,3-dihydro-1H,5H-pyrido-[3,2,1-ij]quinoline-6-carboxamides. The Synthesis and Effects on Urinary Output.

Continuing a targeted search for new leading structures with diuretic action among tricyclic derivatives of hydroxyquinolines, which are of interest as potential inhibitors of aldosterone synthase, the synthesis of a series of the corresponding pyrido[3,2,1-]quinoline-6-carboxanilides was carried out by amidation of ethyl-7-hydroxy-5-oxo-2,3-dihydro-1,5-pyrido[3,2,1-]quinoline-6-carboxylate with aniline, aminophenols and -alkylsubstituted analogs with high yields and purity. The optimal conditions of this reaction are proposed; they make it possible to prevent partial destruction of the original heterocyclic ester and thereby avoid formation of specific impurities of 7-hydroxy-2,3-dihydro-1,5-pyrido[3,2,1-]quinolin-5-one. To confirm the structure of all substances obtained, elemental analysis, nuclear magnetic resonance (NMR) spectroscopy, and mass spectrometry were used.

Synthesis, Spatial Structure and Analgesic Activity of Sodium 3-Benzylaminocarbonyl-1-methyl-2,2-dioxo-1H-2λ⁶,1-benzothiazin-4-olate Solvates.

In order to obtain and then test pharmocologically any possible conformers of the new feasible analgesic benzyl-4-hydroxy-1-methyl-2,2-dioxo-1-2λ⁶,1-benzothiazine-3-carboxamide, its 4--sodium salt was synthesized using two methods. X-ray diffraction study made possible to determine that, depending on the chosen synthesis conditions, the above-mentioned compound forms either monosolvate with methanol or monohydrate, where organic anion exists in the form of three different conformers. Pharmacological testing of the two known pseudo-enantiomeric forms of the original benzylamide and of the two solvates of its sodium salt was performed simultaneously under the same conditions and in equimolar doses.

The Effective Synthesis of N-(Arylalkyl)-1-R-4-hydroxy-2,2-dioxo- 1H-2λ(6),1-benzothiazine-3-carboxamides as Promising Analgesics of a New Chemical Class.

A new, effective preparative method has been proposed and the synthesis of a series of N-(arylalkyl)-1-R-4-hydroxy-2,2-dioxo-1H-2λ(6),1-benzothiazine-3-car-boxamides has been carried out. It has been shown that amidation of alkyl 1-R-4-hydroxy-2,2-dioxo-1H-2λ(6),1-benzothiazine-3-carboxylates with arylalkyl-amines in boiling xylene proceeds with good yield and purity to the corresponding N-(arylalkyl)-amides. However, the presence of water in the reaction mixture has been shown to cause the formation of specific impurities: N-(arylalkyl)-1-R-2,2-dioxo-1H-2λ(6),1-benzothiazin-4-amines.

Ethyl 5-[(1H-benzoimidazol-2-yl)amino-carbon-yl]-4-hydr-oxy-2-methyl-6-oxo-1-propyl-1,6-dihydro-pyridine-3-carboxyl-ate-ethanol-methanol (4/2/1).

The asymmetric unit of the title compound, 4C(20)H(22)N(4)O(5)·2C(2)H(6)O·CH(4)O, contains two pyridine-3-carboxyl-ate mol-ecules, one ethanol mol-ecule and one methanol mol-ecule disordered about in a centre of symmetry. The pyridinone ring, the carbamide group and the bicyclic fragment in both independent mol-ecules are planar within 0.03 Å due to the formation of intra-molecular O-H⋯O and N-H⋯O hydrogen bonds.