Microwave Induced Synthesis of 3,4-Dihydro-2H-pyran-2-carboxaldehyde: A Versatile Linker for Solid Phase Combinatorial Library

Procedures for the dimerization of acrolein to form 3,4-dihydro-2H-pyran-2-carboxaldehyde by microwave induced synthesis have been developed. Significant rate-enhancement and yield increase were observed. 3,4-Dihydro-2H-pyran-2-carboxaldehyde was obtained in 91% yield under microwave irradiation for 5 minutes instead of 39% yield by reacting at 190 °C for 40 min or at 160 °C for 4 hr.     

Synthesis and characterization of polyesters based on 3,4-dihydro-2H-pyran-2-yl-methanol

Summary Diesters of 3,4-dihydro-2H-pyran-2-yl-methanol with oxalic and phthalic acid were prepared and polymerized. Boron trifluoride etherate, anhydrous ferric chloride, andp-toluene sulfonic acid have been selected as different cationic coinitiators. The resulting polymers can be considered as suitable matrices for controlled drug delivery byin vivo biodegradation. They were characterized and their thermal behaviour was investigated.

---

Synthese und Charakterisierung von Polyestern auf 3,4-Dihydro-2H-pyran-2-yl-methanol-Basis

Zusammenfassung Diester aus 3,4-Dihydro-2H-pyran-2-yl-methanol und Oxal- bzw. Phthalsäure wurden hergestellt und unter der Wirkung von Bortrifluorid-Etherat, wasserfreiem Eisentrichlorid undp-Toluolsulfonsäure als kationischen Koinitiatoren polymerisiert. Die erhaltenen Polymere können als geeignete Matrizen für kontrollierte Wirkstoffabgabe durchin-vivo-Bioabbau fungieren. Sie wurden charakterisiert und ihr thermisches Verhalten wurde untersucht.

     

Synthesis of bioactive magnetic nanoparticles spiro[indoline-3,4′-[1,3]dithiine]@Ni (NO3)2 supported on Fe3O4@SiO2@CPS as reusable nanocatalyst for the synthesis of functionalized 3,4-dihydro-2H-pyran

New bioactive magnetic nanoparticles of spiro[indoline-3,4′-[1,3]dithiine]@Ni (NO₃)₂ supported on Fe₃O₄@SiO₂@CPS were synthesized in five steps. The structure of synthesized magnetic nanoparticles was identified by using Energy-Dispersive X-ray spectroscopy (EDX), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), Thermal Gravimetric Analysis (TGA), Infrared spectroscopy (FT-IR), Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), Vibrating Sample Magnetometer (VSM) and Brunauer Emmett Teller (BET) surface analysis. Antimicrobial activity of the synthesized magnetic nanoparticles based on MIC (Minimum Inhibitory Concentration) and MBC (Minimum Bactericidal Concentration) and MFC (Minimum Fungicidal Concentration) values were also examined. Furthermore, the synthesized magnetic nanoparticles exhibited appropriate catalytic properties in the synthesis of the 3,4-dihydro-2H- pyran derivatives.     

微波促进下2-氨基-3-氰基-4-芳基-4H- 吡喃化合物的一锅法合成

标题化合物可在微波辐射下以良好的产率经一锅法合成，为2-氨基-4H-吡哺类化合物的制备提供了一种快速便捷的有效方法。     

Synthesis of New Fused 1,5-Benzodiazepines,Part 3

1,3-Dihydro-4-phenyl-1,5-benzodiazepin-2-one 1 _a was treated with some ylidenecyanothioacetamides to give the corresponding pyrido(2,3-b)benzodiazepines 3– 6. Treatment of compound 1 _a with a mixture of thiophen-2-aldehyde and thiourea or guanidine gave the corresponding 1,3-thiazino- and pyrimido(4,5-b)benzodiazepines 7 and 8. 3-Arylidene derivatives 9 _a–e and 10 were synthesized. Compound 10 was subject to react with 2-(1-methylthio-1′-anilinomethylidene)malononitrile to give oxazino-benzodiazepine 11. Thieno(3,2-b)benzodiazepines 12 _a,b and 13 were synthesized via the reaction of compound 1 _b with sulfur and some active nitriles. [1,3-Dihydro-4-phenyl(1,5)-benzodiazepin-2-ylidene]malononitrile 15was used as synthon to obtain novel pyrido-, pyrano-, benzo-, and thienobenzodiazepines 16–20, respectively. The reaction of compound 1 _b with CS ₂ or PhNCS along with 1,1,3-tricyano-2-aminoprop-1-ene, 2-(1-methylthio-1′-anilinomethylidene)malononitrile, or 1,3-dibromopropane gave the corresponding polyfused benzodiazepines 21– 23, respectively.     

Iodine-Catalyzed Aza-Diels–Alder Reactions of Aliphatic N-Arylaldimines

Iodine-catalyzed aza-Diels–Alder (Povarov) reaction of 3,4-dihydro-2H-pyran with in situ generated N-arylimines containing enolizable protons is described. This has given an easy way to introduce C-2 aliphatic substitution in tetrahydroquinolines.     

Synthesis of New 3,4-Disubstituted Furazans

A series of new 3,4-substituted furazans was synthesized on the basis of the mutual transformations of the functional groups in halogenomethyl and bisacyl derivatives of furazan.     

Synthesis of 2-diphenylphosphinoyl-3,5-diaryl-3,4-dihydro-2H-telluropyrans by reaction of chalcones with bis[(diphenylphosphinoyl)methyl]telluride

The NaH-promoted tandem Michael addition/intramolecular Wittig-Horner reaction of bis[(diphenylphosphinoyl) methyl]telluride with chalcones stereoselectively afforded trans-2-diphenylphosphinoyl-3,5-diaryl-3,4-dihydro-2H-telluropyran derivatives in 51-72% yield, under mild conditions.     

The preparation of 5-(2-aminophenyl)-1,3,4-oxadiazole-2(3H)-one and its rearrangement to 3-amino-2,4(1H,3H)-quinazolinedione

When anthranilic acid hydrazide is reacted with 1,1-carbonyldiimidazole inTHF 5-(2-aminophenyl)-1,3,4-oxadiazole-2(3H)-one (4) is formed. It can also be prepared from 1-o-aminobenzoyl-4,4-dimethylsemicarbazide which eliminates methylamine when boiled withDMF. On heating the 5-(2-aminophenyl)-1,3,4-oxiadiazole above its melting point it rearranges to 3-amino-2,4(1H,3H)-quinazolinedione (5).

---

Die Darstellung von 5-(2-Aminophenyl)-1,3,4-oxadiazol-2(3H)-on und dessen Umlagerung in 3-Amino-2,4(1H,3H)-chinazolindion

Zusammenfassung Bei der Reaktion von Anthranilsäurehydrazid mit 1,1-Carbonyldiimidazol inTHF wird 5-(2-Aminophenyl)-1,3,4-oxadiazol-2(3H)-on (4) gebildet. Dieses kann auch aus 1-o-Aminobenzoyl-4,4-dimethylsemicarbazid dargestellt werden, welches beim Kochen mitDMF Methylamin eliminiert. Beim Erhitzen von 5-(2-Aminophenyl)-1,3,4-oxadiazol über seinen Schmelzpunkt tritt Umlagerung zu 3-Amino-2,4(1H,3H)-chinazolindion (5) ein.

     

Eine einfache synthese von 3,4-Dihydro-5(1H)-pyrromethenonmodellen

Starting from monocyclic precursos a model of 3,4-dihydro-5(1 H)-pyrromethenones, important partial-structures of 2,3-bilatrienes-abc, is prepared by a four-step-synthesis.

     

醋酸锌催化串联反应合成2-氨基-3-氰基-4H-吡喃类衍生物

以氰基查尔酮类化合物及丙二腈为原料,醋酸锌为催化剂,经串联反应合成2-氨基-4H-吡喃类衍生物。考察催化剂、溶剂、反应时间及温度、原料摩尔比对产率的影响。最优条件为：氰基查尔酮类化合物与丙二腈物质的量比为1.0:1.0,醋酸锌(10mol%)作催化剂,二氯甲烷作溶剂,反应温度为30℃,产率最高为99.5%。     

Synthesis of 2-diphenylphosphinoyl-3,5-(diaryl)-3,4-dihydro-2H-thiopyrans by the reaction of a bis[(diphenylphosphinoyl)methyl]sulfide with chalcones

The NaH-promoted tandem Michael addition/intramolecular Horner-Wittig reaction of bis(diphenylphosphinoylmethyl)sulfide with chalcones afforded 3,4-dihydro-2H-thiopyrans 3a-l in 78-88% yield.     

Synthesis of substituted 2-aroyl-3-methylchromen-4-ones from isovanillin via 2-aroyl-3-methylchroman intermediates

The synthesis of substituted 2-aroyl-3-methylchromen-4-one from isovanillin is described. O-Allylphenol (2) prepared from isovanillin (1) was allowed to react with various α-bromoacetophenone (3) to produce 2-(2-allyl-3,4-dimethoxy)phenoxy-1-aroylethanones (4). The resultant 4 were treated with 2 equiv of potassium tert-butoxide to afford the substituted 2-aroyl-3-methylchromans (5) through an isomerization of an allylic double bond and a carbanion-olefin intramolecular 6-endo-trig cyclization reaction. Subsequently, resultant 5 were oxidized with DDQ to yield the title compound 6, in good over-all yields.     

Facile Synthesis and Adsorption Properties of Phosphonated Cellulose Beads for Selective Removal of Low-density Lipoprotein

Hyperlipemia, which induced by the abnormally elevated level of lipids in plasma such as cholesterol and triglyceride (TG), now has been widely recognized as a major risk factor of coronary heart disease1. Low-density lipoprotein (LDL) particles are the m…     

高效液相色谱法测定人血浆中的辛伐他汀

 建立了高效液相色谱法监测人口服辛伐他汀药物后的血药浓度。血样用环己烷-二氯甲烷(体积比为3.5∶1)提取,以洛伐他汀为内标,在237nm波长下检测;色谱柱:LichrospherC18(200mm×4.6mmi.d.,5μm),流动相:乙腈-水(体积比为70∶30);流速:1.2mL/min。血药浓度在0.25～50.0μg/L范围内与峰面积和内标峰面积的比值之间线性关系良好,日内及日间相对标准偏差(n=5)分别低于7.94%和8.58%,回收率高于93.3%。方法灵敏、准确、快速,适用于药物动力学和药效学研究。     

A New Method for the Synthesis of Antihypercholesterolemic Agent Simvastatin

A new synthetic method for the preparation of the cholesterol‐lowering drug simvastatin from the naturally occurring lovastatin is reported. The synthesis employs first the protection of the OH group of lovastatin ( 1 ) and then the protection of the lactone C?O group to prevent enolization via conversion to the orthoesters 4a and 4b . Alkylation of the 2‐methylbutyrate side chain is then successfully achieved. Removal of the protecting groups affords antihypercholesterolemic agent simvastatin ( 2 ).     

Mild and Efficient Syntheses of 1-Aryl-3,4-dihydroisoquinolines and 1-Aryl-3,4-dihydro-β-carbolines via Regiospecific β-Eliminations of the Corresponding N-Tosyl-1,2,3,4-tetrahydroisoquinolines and N-Tosyl-1,2,3,4-tetrahydro-β-carbolines

Treatment of N-tosyl-1-aryl-1,2,3,4-tetrahydro-isoquinolines or N-tosyl-1-aryl-1,2,3,4-tetrahydro-β-carbolines with a strong base such as NaOH or KOH at 70 °C in dimethylsulfoxide (DMSO) produced 1-aryl-3,4-dihydroisoquinolines or 1-aryl-3,4-dihydro-β-carbolines in good yields via mild and regiospecific β-eliminations. A dramatic solvent effect was observed, DMSO was crucial for the reactions. The temperature is also crucial for the reactions and should be kept between 60 and 80 °C.     

Synthesis of 4-thia analogues of isoquinoline alkaloids

Summary (±)-4-Thiacarnegin (3) was synthesized by reaction of 6,7-dimethoxy-3-methyl-2H-1,3-benzothiazinium iodide (2) with methyl magnesium iodide, thereby opening a new synthetic route to 4-substituted dihydro-2H-1,3-benzothiazines. Compound3 was also obtained by reduction of 6,7-dimethoxy-3,4-dimethyl-2H-1,3-benzothiazinium iodide (5). In a similar way, reduction of the quaternary salts9 a–c afforded the (±)-4-thia analogues of cryptostilin-I, -II and -III (10 a–c). The isomers of the former compounds (12 a–c) were also synthesized by reduction of the 4H-1,3-benzothiazinium salts11 a–c.

---

Synthese von 4-Thiaanalogen von Alkaloiden mit Isochinolingerüst

Zusammenfassung Aus 6,7-Dimethoxy-3-methyl-2H-1,3-benzothiaziniumjodid (2) wurde mit Methylmagnesiumjodid (±)-Thiacarnegin (3) dargestellt. Diese Reaktion bietet ein neues Verfahren für die Synthese von 4-substituierten Dihydro-2H-1,3-benzothiazinen.3 wurde auch durch Reduktion von 6,7-Dimethoxy-3,4-dimethyl-2H-1,3-benzothiaziniumjodid (5) erhalten. Die Reduktion der quartären Ammoniumsalze9 a–c ergab ebenfalls die Cryptostillin I-, II-, III-(±)-4-thiaanalogen Verbindungen (10 a–c). Reduktion der 4H-1,3-Benzothiazinium-Salze11 a–c lieferte die entsprechenden Isomeren12 a–c der obengenannten Verbindungen.