New 3-alkylamino-4H-thieno-1,2,4-thiadiazine 1,1-dioxide derivatives activate ATP-sensitive potassium channels of pancreatic beta cells

Compound 1a (NN414) is a potent opener of Kir6.2/SUR1 K(ATP) channels. Compound 1a inhibits insulin release in vitro and in vivo and preserves beta cell function in preclinical animal models suggesting that such a compound could find use in treatment or prevention of type 1 and type 2 diabetes. The crystal structure and a convergent synthesis of 1a are presented together with a range of new analogues of 1a. Several compounds, e.g., 6-chloro-3-(1-methyl-1-phenylethyl)amino-4H-thieno[3,2-e]-1,2,4-thiadiazine 1,1-dioxide (1h), were found to be potent openers of Kir6.2/SUR1 K(ATP) channels and were able to suppress glucose-stimulated insulin release from rat islets in vitro (EC(50) = 0.04 +/- 0.01 muM) and in vivo after intravenous or peroral administration to hyperinsulinemic obese Zucker rats (ED(50) = 4.0 mg/kg). Structural modifications of this series of K(ATP) channel openers have provided compounds with promising pharmacokinetic properties indicating that brief periods of beta cell rest can be achieved.     

A novel system: 2H-pyrido[3,2-e]-1,2-thiazine-1,1-dioxide. Synthesis and properties of some derivatives

A rearrangement of 2H-2-acetonyl(phenacyl)-4,6-dimethyl- pyrido[3,2-d]isothiazoline-3-one-1,1-dioxides (I), (II) to derivatives of the unknown system of 2H-pyrido[3,2-e]-1,2-thiazine-1,1-dioxide (V), (XIII) is described; the synthesis of 2-N-substituted derivatives (VI - XII), (XIV - XVI) is also given. The structures of the new compounds were confirmed with elemental analyses and spectral data (I.R., N.M.R., MS). Some of the newly obtained compounds showed strong analgesic activity upon pharmacological screening.     

Three-dimensional quantitative structure-activity relationships of ATP-sensitive potassium (KATP) channel openers belonging to the 3-alkylamino-4H-1,2,4-benzo- and 3-alkylamino-4H-1,2,4-pyridothiadiazine 1,1-dioxide families

Recent studies have demonstrated that selective activation of pancreatic ATP-sensitive potassium (KATP) channels could be of clinical value in the treatment of type I and type II diabetes, obesity, and hypersinsulinemia. Taking into account these promising therapeutic opportunities, we have explored the 3-alkylamino-4H-1,2,4-pyrido- and 3-alkylamino-4H-1,2,4-benzothiadiazine 1,1-dioxide families. Among these series, numerous drugs were identified as highly potent and selective openers of either the pancreatic or the aortic KATP channels. Thanks to comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA), quantitative structure-activity relationship approaches using more than 100 compounds, pharmacophoric models explaining the activity and selectivity of the drugs have been elaborated. These models highlighted the importance of several chemical regions for KATP channel activation and could be very helpful for future improvement of drug potency, selectivity, or both. Moreover, an original CoMSIA analysis, using a selectivity index (SI) as a dependent variable, was also performed with the aim of identifying the structural parameters influencing tissue selectivity.     

6-Chloro-1,2,4-triazolo[4,3-b]pyrido[2,3-d]-and [3,2-d]pyridazines - Synthesis and Structure Determination

5,8-Dichloropyrido[2,3-d]pyridazine ( 2 ) gave with hydrazine hydrate in dioxane 5-chloro-8-hydrazino- and 8-chloro-5-hydrazinopyrido[2,3-d]pyridazines 3 and 4 . When 3 and 4 were allowed to react with formic acid they gave a mixture of the 6-chloro-1,2,4-triazolo[4,3-b]pyrido[2,3-d] - and [3,2-d]pyridazines ( 5 and 6 ).     

Synthesis and properties of some derivatives of 2H-4,6-dimethylpyrido[3,2-d]isothiazolin-3-one-1,1-dioxide

The synthesis of 2H-4,6-dimethylpyrido[3,2-d]isothiazolin-3-one-1,1-dioxide and its 2-N-substituted derivatives are described. Structures of the obtained compounds were determined on the basis of elemental analyses and spectral data I.R., N.M.R., MS. Preliminary information on the pharmacological properties of the obtained compounds also given.     

3-Alkylamino-4H-pyrido[2,3-e]-1,2,4-thiadiazine 1,1-dioxides structurally related to diazoxide and pinacidil as potassium channel openers acting on vascular smooth muscle cells: design, synthesis, and pharmacological evaluation

A series of 3-alkylamino-4H-pyrido[2,3-e]-1,2,4-thiadiazine 1, 1-dioxides structurally related to diazoxide and pinacidil were synthesized and tested as possible K(ATP) channel openers on isolated pancreatic endocrine tissue as well as on isolated vascular, intestinal, and uterine smooth muscle. In contrast to previously described 3-alkylamino-4H-pyrido[4,3-e]-1,2,4-thiadiazine 1, 1-dioxides, most of the new compounds were found to be poorly active on B-cells but exhibited clear vasorelaxant properties. 3-(3, 3-Dimethyl-2-butylamino)-4H-pyrido[2,3-e]-1,2,4-thiadiazine 1, 1-dioxide (4d) and 7-chloro-3-(3, 3-dimethyl-2-butylamino)-4H-pyrido[2,3-e]-1,2,4-thiadiazine 1, 1-dioxide (5d), two compounds bearing the alkyl side chain of pinacidil, were found to be the most active representatives of their respective series on rat aorta rings. 3-Cycloalkylalkylamino- and 3-aralkylamino-7-chloro-4H-pyrido[2,3-e]-1,2,4-thiadiazine 1, 1-dioxides also expressed myorelaxant activity on electrically stimulated guinea pig ileum and on oxytocin-induced contractions of the rat uterus. Further biological investigations ((86)Rb efflux measurements, vasodilator potency on 30 and 80 mM KCl-induced contractions in the absence and presence of glibenclamide) revealed that compounds 4d and 5d, but not compound 5f, expressed the pharmacological profile of classical K(ATP) channel openers. In conclusion, by changing the position of the nitrogen atom in the pyridine ring, we now have obtained a family of drugs expressing an opposite tissue selectivity. Taken as a whole, the present findings also suggest that 3-alkylamino-4H-pyrido[2,3-e]-1,2,4-thiadiazine 1, 1-dioxides such as 4c, 4d, 5c, and 5d may be considered as new examples of K(ATP) channel openers expressing a pharmacological profile similar to that of pinacidil and diazoxide.     

Synthesis and properties of 3-aminomethyl derivatives of 3H-2-imino-7-methyl-4-oxopyrido-[3,2-e]-1,3-thiazine-5- and -6-carboxylic acids

It was stated that esters of 3H-2-imino-7-methyl-4-oxopyrido [3,2-e]-1,3-thiazine-5- and -6-carboxylic acids (I, II) undergo the Mannich reaction giving the corresponding 3-aminomethyl derivatives (III-XIV). Derivatives of ester II [(XII) and (XIV)] showed distinct analgesic and antiserotonic activities.     

Synthesis and properties of new 3-acyl- and 3-carbamoyl derivatives of esters of 3H-2-imino-7-methyl-4-oxopyrido[3,2-e]-1,3-thiazine-5- and -6-carboxylic acids

It was stated that esters of 3H-2-imino-7-methyl-4-oxopyrido[3,2-e]-1,3-thiazine-5- and -6-carboxylic acids react with acyl anhydrides and chlorides giving 3-acyl derivatives. Reaction of the above mentioned esters with isocyanates affords the corresponding 3-carbamoyl derivatives.     

Synthesis of 6-(Ethoxymethylenimino)-1,2,4-triazolo[3′,4′:5,1]-[1,2,4]triazolo[4,3-a]quinazolin-7(6H)-one

As a progressive continuation of our study in the condensed quinazolinone series^{1, 2)}, we recently described the synthesis and antihypertensive activity of some 4-amino[1,2,4]triazolo[4,3-a]quinazolin-5(4H)-one derivatives ( 1a-c , R=H, OH, SH). Now, we wish to report the conversion of one of these derivatives, namely 4-amino-1-mercapto-[1,2,4]-triazolo[4,3-a]quinazolin-5(4H)-one (1c) into a more complicate condensed quinazolinone system.     

3-(氨基烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物的设计、合成与乙酰胆碱酯酶抑制活性

目的初步探讨在7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物母核C-3位苯环侧链中引入二乙胺基团的3-(氨基烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物的合成及其乙酰胆碱酯酶抑制活性。方法以取代的苯甲醛和乙酰甘氨酸为初始原料,经Erlenmeyer-Plchl反应、缩合反应、水解反应、缩合反应,生成6-芳甲基-3-硫代-1,2,4-三嗪-5(2H)-酮类化合物,再与取代的α-氯代苯乙酮反应,得到6-芳甲基-3-(羟基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物;以芳基乙烯为原料,经温和的氧化反应、缩合反应得到3,4-二氢-6-芳基-3-硫代-1,2,4-三嗪-5(2H)-酮类化合物,再与取代的α-氯代苯乙酮在乙酸中反应得到6-芳基-3-(羟基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物。两条合成路线得到的3-(羟基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物进一步经Williamson反应制备得到10个3-(烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物。所有目标化合物结构均经质谱、红外光谱和核磁共振氢谱确证。采用Ellman法对目标化合物进行体外乙酰胆碱酯酶抑制活性筛选。结果根据前期已筛选化合物的活性数据和总结出的初步构效关系,设计并合成了10个C-3位苯环侧链中含有二乙胺基团的3-(氨基烷氧基芳基)-7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物。体外乙酰胆碱酯酶抑制活性筛选表明,所有目标化合物均具有乙酰胆碱酯酶抑制活性,其中7个化合物在10μmol.L-1浓度水平抑制活性超过了50%。结论根据体外重组人源AChE(rhAChE)抑制活性的测试结果,发现C-3位苯环侧链中含有二乙胺基团的7H-噻唑并[3,2-b]-1,2,4-三嗪-7-酮类化合物均具有较好的rh-AChE抑制活性。在这一位置的侧链中引入二乙胺基团,可以增强化合物对rhAChE的抑制活性。     

Synthesis, characterization and antiinflammatory-analgesic properties of 6-(alpha-amino-4-chlorobenzyl)thiazolo [3,2-b]-1,2,4-triazol-5-ols

A series of 6-(alpha-amino-4-chlorobenzyl)-thiazolo[3,2-b]-1,2,4-triazol-5-ols (2a-j) were synthesized from 6-(4-chlorobenzylidene) thiazolo[3,2-b]-1,2,4-triazolo-5(6H)-one (2) by applying Michael addition reaction. All the compounds were characterized by their melting points, elementary analysis, IR and 1H-NMR spectra and screened for their anti-inflammatory and analgesic activities. Among the derivatives compound 2i bearing 4-(4-acetylphenyl)piperazine showed the highest and dose-dependent analgesic and anti-inflammatory activity without inducing any gastric lesion.     

Synthesis and pharmacological activities of some new 2-[1-(6-methoxy-2-naphthyl)ethyl]-6-(substituted)benzylidene thiazolo[3,2-b]-1,2,4-triazole-5(6H)-one derivatives

In this study, thirteen new compounds having a 2-[1-(6-methoxy-2-naphthyl)ethyl]-6-(substituted)benzylidenethiazolo[3,2-b]- 1,2,4-triazole-5(6H)-one structure were synthesised using N-[2-(6-methoxy-2-naphthyl)propanoyloxysuccinimide, N-[2-(6-methoxy-2-naphthyl)propanoyl]thiosemicarbazide and 3-[1-(6-methoxy-2-naphthyl)ethyl]-5-mercapto-1,2,4-triazole. The structures and physical properties of the compounds were elucidated by IR, 1H NMR, mass spectroscopy and elemental analysis. The antiinflammatory activity and gastric ulceration potential of the compounds were tested using naproxen as a reference compound.     

Syntheses and gastric acid antisecretory properties of the H2-receptor antagonist. N-[3-[3-(1-piperidinylmethyl)phenoxy]propyl]thieno[3,4-d]isot hiazol-3-amine 1,1-dioxide and related derivatives

The synthesis and gastric acid antisecretory properties of several N-substituted thieno[3,4-d]isothiazol-3-amine 1,1-dioxides and analogues are described. Two of the more potent compounds, N-[3-[3-(1-piperidinylmethyl)phenoxy]propyl]thieno[3,4-d] isothiazol-3-amine 1,1-dioxide (6a) and N-[4-[3-(1-piperidinylmethyl)phenoxy]propyl]thieno[3,4-d] isothiazol-3-amine 1,1-dioxide, showed greater potencies as H2-receptor antagonists (in vitro) than ranitidine. They also had potent gastric acid antisecretory activities in vivo, inhibiting basal acid secretion in the rat, histamine-stimulated acid secretion in the dog, and food-stimulated acid secretion in the dog. These were selected for further pharmacological evaluation.     

Synthesis of 8-benzylamino-1,2-dihydro-10-oxo-2,2,5-trimethyl-4H-pyrano[4′3′∶4,5]pyrido[3,2-e]-1,3-thiazine and its psychotropic activity

Translated from Khimiko-farmatsevticheskii Zhurnal, Vol. 28, No. 1, pp. 20–22, January, 1994.     

Analyses of drugs by polarographic methods, XXXI. Electroanalysis of brotizolam, 2-bromo-4-(2-chlorophenyl)-9-methyl-6H-thieno[3,2-ss]-1,2, 4-triazolo[4,3-alpha]-1,4-diazepine

Britton-Robinson buffers (BRB), pH 4–9, provide for sufficient stability of brotizolam ( 1 ) and may be used as supporting electrolytes for its DC_t polarography. The polarographic behaviour of 1 was investigated: The i-E curves are markedly influenced by adsorption processes and cleavage of the C-Br bond. In spite of these difficulties a precise electrochemical method for the determination of 1 could be developed. A BRB (pH 6.3) is best suited for the assay by DC_t and DPP. The lower sensitivity limit is 10^?6 mol ± L^?1 with DC_t polarography and 10^?7 mol ±±±± L^?1 with DPP. In the analysis of single 0.25 mg tablets the relative standard deviation S_rel, is ± 0.76% (DC_t) or ± 0.89% (DPP). Therefore, both polarographic methods are most suitable for the content uniformity test (USP XXI).