Efficient,Stereoselective Approach to the Synthesis of 3-(1-Phenyl-2-(Z-styrylsulfonyl)-1H-imidazol-4-yl)-2H-chromen-2-ones

Reaction of phenyl acetylene with 3-(1-aryl-2-mercapto-4-imidazolyl)-2H-1-benzopyran-2-ones (4) in the presence of sodium hydroxide in absolute ethanol led to the formation of 3-(1-phenyl-2-(Z-styrylthio)-1H-imidazol-4-yl)-2H-chromen-2-ones (6) in excellent yields. These, on further oxidation with H₂O₂/AcOH, gave the corresponding sulfones (7) with retention of stereochemistry.

Synthesis and characterization of polymeric triphenyltin and cyclotetrameric tricyclohexyltin 2-(1H-imidazol-1-yl)acetates

The reaction of 2-(1H-imidazol-1-yl)acetic acid with (Ph₃Sn)₂O or Cy₃SnOH (Cy?=?cyclohexyl) yields triphenyltin 2-(1H-imidazol-1-yl)acetate (1) and tricyclohexyltin 2-(1H-imidazol-1-yl)acetate (2), respectively. 2-(1H-imidazol-1-yl)acetates in these two complexes show remarkably different coordination modes. Complex 1 forms a polymeric chain structure through intermolecular Sn–N interactions, while 2 displays a 28-membered macrocyclic tetranuclear structure by the assembly of Sn–N coordination bonds.     

Über Reaktionen von Arylbiguaniden mit Benzoin beimpH der Biguanidbasen

Summary Arylbiguanides2 a–e react with benzoin (1) at thepH of the base to two different products.1 undergoes in presence of the base2 a–e oxidation to benzil and benzoic acid, which reacts fast with the arylbiguanides2 a–e to yield N-[4-(arylamino)-6-phenyl-1,3,5-triazine-2-yl]benzamides3 a–d. After lowering thepH of the reaction mixture, the bases2 b–e react with benzil to yield 2-[1-aryl-5-oxo-4,4-diphenyl-2-imidazoline-2-yl]guanidine4 b–e. The mechanism of the formation is discussed. The structure of4b was established from a single crystal x-ray structure analysis. The analysis was carried out at 100K: C₂₃H₂₁N₅O,M _r=383.5, monoclinic, C 2/c,a=15.842(6),b=8.419(3),c=30.223(10) Å, =98.44(3)°,V=3 987.3(9) ų,Z=8,d _x=1.277 g/cm³, =0.81 cm^–1,R=5.89%R _w=4.97% (1 537 observations, 233 parameters).

     

Über Reaktionen von Alkylbiguaniden mit Benzoin beimpH der Biguanidbasen

Summary Alkylbiguanides2 a–e react with benzoin (1) at thepH of the base in different ways.1 undergoes in presence of2 a, c oxidation to benzoic acid which reacts with the bases2 a, c to yield 4-phenyl-1,3,5-triazinamines3 c, 4 c; in presence of2 b 1 is transformed to benzil, which reacts with2 b under rearrangement to yield 1-(4-oxo-5,5-diphenyl-2-imidazolin-2-yl)-3,3-dimethylguanidine (5 b). However, the cycloalkylbiguanides2 d, e, react in presence of nitrogen as well as oxygen with1 to yield piperidine-1-[N-(4,5-diphenylimidazol-2-yl)-carboxamidine] (7 d), resp. morpholine-4-[N-(4,5-diphenylimidazol-2-yl)-carboxamidine] (7 e). The structure of7 e was established by means of an X-ray structure analysis. All proton- and carbon resonances were assigned on the basis of 2-dimensional NMR data.

     

Eine einfache Synthese von 11H-Indolo[3,2-c]chinolin-6-onen

11H-Indolo[3,2-c]quinolin-6-ones, which are containing the -carboline ring system, can be easily synthesized from 4-azido-3-phenyl-2(1H)-quinolones, which are obtained in a two step reaction from 4-hydroxy-3-phenyl-2(1H)-quinolones. Cyclization of the azides can be realized by irradiation or thermal reaction.

     

Preparation of Isoquinolin-(2(1H)-yl)but-2-enedioate Derivatives

One-pot, three-component reactions of isoquinoline, dimethyl/diethyl acetylenedicarboxylate, and indole, carbazole, pyrazole, or imidazole gave dimethyl/diethyl 2-(1-(1H-indol-1-yl)isoquinolin-2(1H)-yl)but-2-enedioate, dimethyl/diethyl 2-(1-(9H-carbazol-9-yl)isoquinolin-2(1H)-yl)but-2-enedioate, dimethyl 2-(1-(1H-pyrazol-1-yl)isoquinolin-2(1H)-yl)but-2-enedioate, or dimethyl 2-(1-(1H-imidazol-1-yl)isoquinolin-2(1H)-yl)but-2-enedioate respectively in good to excellent yields.     

Cleavage of 2-(1,2,3,4-tetrahydroisoquinolin-1-yl)-2-phenyl-1,3-dithianes with HgO/BF3

Summary The title compounds (5) were prepared by addition of 2-phenyl-1,3-dithiane anion (2-lithiated10) to adequately substituted N-alkyl-3,4-dihydroisoquinolinium salts (7a–7g). Cleavage of compounds5 with HgO/BF₃ affords S-benzoyl-1,3-propanedithiol (4a) and the corresponding disulfide4c, benzaldehyde, and Hg(I) ions. In contrast to the title compounds, 2-(-dialkylaminobenzyl)-2-phenyl-1,3-dithianes (6) yield benzil under these conditions.In commemoration of the late Prof. Dr. Dr. h.c. mult.Horst Böhme, Marburg/Germany, an outstanding representative of Pharmaceutical Chemistry     

Synthesis of 1-(3-(1,2,4-triazol-1-yl)-2,3,6-trideoxy-L-arabino-hexofuranosyl)uracils via an α,β-unsaturated aldehydrohexose

Summary Mercuric catalyzed hydrolysis of acetylatedL-rhamnal1 gave the ,-unsaturated aldehyde2. 1,2,4-Triazole was coupled, in a Michael type addition reaction, to2 at C-3 in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) to give, after acetylation at the anomeric center, an anomeric mixture of 1,5-di-O-acetyl-3-(1,2,4-triazol-1-yl)-2,3,6-trideoxy-L-arabino-hexofuranose (3). Reaction of3 with silylated 2,4-dihydroxypyrimidines4 in the presence of trimethylsilyl triflate as catalyst followed by deprotection with 33% methylamine in absolute ethanol afforded the corresponding nucleosides7 and8.

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Synthese von 1-(3-(1,2,4-Triazol-1-yl)-2,3,6-trideoxy-L-arabino-hexofuranosyl)uracilen über eine ,-ungesättigte Aldohexose

Zusammenfassung Die quecksilberkatalysierte Hydrolyse von acetyliertemL-Rhamnal1 ergab die ,-ungesättigten Aldehyde2. 1,2,3-Triazol wurde in Gegenwart von 1,8-Diazabicyclo[5.4.0]-7-undecen mittels einer Addition vom Michael-Typ an C-3 von2 gekoppelt und ergab dann nach Acetylierung am anomeren Zentrum eine anomere Mischung von 1,5-Di-O-acetyl-3-(1,2,4-triazol-1-yl)-2,3,6-trideoxy-L-arabino-hexofuranose (3). Die Reaktion von3 mit silyliertem 2,4-Di-hydroxypyrimidinen4 in Gegenwart von Trimethylsilyltriflat in absolutem Ethanol ergab die entsprechenden Nucleoside7 und8.

     

The crystal structures ofbis-{(2-benzotrifluoride)-[(2-oxo-3H-naphth-3-ylidene)-methyl]-aminato} Copper(II) andbis-{(3-benzotrifluoride)-[(2-oxo-3H-naphth-3-ylidene)-methyl]-aminato} Copper(II)

Summary TheSchiff base ligands 3-[(2-benzotrifluoride)-2-hydroxy-3H-naphth-3-ylidene)-methyl] aldamine (1) and 3-[(3-benzotrifluoride)-2-hydroxy-3H-naphth-3-ylidene)-methyl] aldamine (2) and their corresponding Cu(II) complexes (I, II) were synthesized. The crystal structures ofbis-{(2-benzotrifluoride)-[(2-oxo-3H-naphth-3-ylidene)]-methyl]-aminato} Copper(II) (I) andbis-{(3-benzotrifluoride)-[(2-oxo-3H-naphth-3-ylidene)-methyl]-aminato} Copper(II) (II) were determined. CompoundI crystallizes in the triclinic crystal system (a=12.561(3),b=16.211(4),c=8.007(2) Å, =96.29(2), =101.42(2), =97.10(2)°, space group ,Z=2); compoundII crystallizes in the monoclinic crystal system (a=5.064(2),b=19.172(4),c=15.111(3) Å, =95.05(2)°, space group P2₁/c,Z=2). The X-ray diffraction study shows that the geometry around the metal atom is square planar for both copper complexes.

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Kristallstruktur vonbis-{(2-Benzotrifluorid)-[(2-oxo-3H-naphth-3-yliden)-methyl]-aminato}-Kupfer(II) undbis-{(3-Benzotrifluorid)-[(2-oxo-3H-naphth-3-yliden)-methyl]-aminato}-Kupfer(II)

Zusammenfassung DieSchiffschen Basen 3-[(2-Benzotrifluorid)-2-hydroxy-3H-naphth-3-yliden)-methyl]-aldamin (1) und 3-[(3-Benzotrifluorid)-2-hydroxy-3H-naphth-3-yliden)-methyl]-aldamin (2) sowie ihre entsprechenden Cu(II)-Komplexe (I,II) wurden synthetisiert und ihre Struktur im Kristall bestimmt. VerbindungI kristallisiert triklin (a=15.561(3),b=16.211(4),c=8.007(2) Å, =96.29(2), =101.42(2), =97.10(2)°, Raumgruppe ,Z=2); VerbindungII kristallisiert monoklin (a=5.064(2),b=19.172(4),c=15.111(3) Å, =95.05(2)°, Raumgruppe P2₁/c,Z=2). Aus der Röntgenstrukturanalyse ergibt sich eine quadratisch planare Geometrie der Komplexe.

     

TheSemmler-Wolff aromatization andSchmidt reaction applied to some pyrido[2′,3′:3,4]pyrazolo[5,1-c][1,2,4]benzotriazines

Pyrido[2,3:3,4]pyrazolo[5,1-c][1,2,4]benzotriazin-4(1H)ones were transformed via their oximes in aSemmler-Wolff aromatization process in the tetracyclic heteroaromatic amines4 or bySchmidt reaction into a mixture of the same amine4 and a ring enlarged lactam3. Syntheses of some halo pyrazolo[3,4-b]pyridines and a photochemical transformation of 3-azidopyrazolo[3,4-b]pyridine are also described.

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Über dieSemmler-Wolff- undSchmidt-Reaktion einiger Pyrido[2,3:3,4]pyrazolo[5,1-c][1,2,4]benzotriazine

Zusammenfassung Pyrido[23:3,4]pyrazolo[5,1-c][1,2,4]benzotriazin-4(1H)one werden über Oxime in einerSemmler-Wolff-Reaktion in die tetracyklischen aromatischen Amine4 umgewandelt. In einerSchmidt-Reaktion wurden dieselben Ketone in ein Gemisch aus Amin4 und Lactam3 übergeführt. Synthesen von halogensubstituierten Pyrazolo[3,4-b]pyridinen und photochemische Umwandlung von 3-Azidopyrazolo[3,4-b]pyridin werden beschrieben.

     

Synthesis of 5′-amino- and 5′-azido-2′,5′-dideoxy nucleosides from thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione

Summary Thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (4) was silylated and condensed with methyl 5-azido-2,5-dideoxy-3-O-(4-methylbenzoyl)-D-erythro-pentofuranoside (2) in the presence ofTMS triflate to afford the corresponding protected nucleoside6 and acyclic nucleoside7. Deprotection of6 with MeONa/MeOH at room temperature gave 1-(5-azido-2,5-dideoxy--D-erythro-pentofuranosyl)-thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (8) and the corresponding anomer9, whereas compound7 yielded 5-azido-2,5-dideoxy-1-(2,4-dioxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidin-1-yl)-1-O-methyl-D-erythro-pentitol (10) under the same reaction conditions. 1-(5-Amino-2,5-dideoxy--D-erythro-pentofuranosyl)thieno[2,3-d]pyrimidine-2,4(1H,3H)-dione (11) was obtained on treating9 with Ph₃P in pyridine followed by hyrolysis with NH₄OH. The anomeric nucleosides14 and15 and the corresponding acyclic nucleoside16 were obtained when4 was trimethylsilylated and condensed with methyl 2-deoxy-3,5-di-O-(4-methylbenzoyl)-D-erythro-pentofuranoside (3) followed by deprotection with MeONa in MeOH. Compounds8 and9 were also obtained when the anomeric mixture14/15 was treated with a mixture of NaN₃, Ph₃P, and CBr₄ in dryDMF at room temperature.On leave from Chemistry Department, Faculty of Science, Tanta University, Tanta, Egypt     

Diborane as a reducing agent IX: Reduction of aTris(trifluoroacetyl)enaminospiroindoline

Summary Reduction of the title compound (2) with diborane furnishes 1-trifluoroethyl-3-(2-(trifluoroethylamino)ethyl)-3-vinylindoline (4), 1-hydroxy-trifluoroethyl-3-(2-(trifluoroethylamino)ethyl)indole (5), and 1-methyl-2-trifluoroethyl-1,2,3,4-tetrahydro--carboline (6). However, treatment of2 with lithium aluminum hydride, H₂/Pd on charcoal, and sodium borohydride affords hydroxyspiroindolenine8, hydroxy-bis(trifluoroacetyl)enaminospiroindoline9, andN-ethyltryptamine7, respectively. The results are discussed and the mechanisms of the reactions leading to4–8 are presented.

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Diboran als Reduktionsmittel, 9. Mitt.: Reduktion einesTris(trifluoroacetyl)enaminospiroindolins

Zusammenfassung Reduktion der Titelverbindung (2) mit Diboran ergibt 1-Trifluoroethyl-3-(2-(trifluoroethylamino)ethyl)-3-vinylindolin (4), 1-Hydroxy-trifluoroethyl-3-(2-(trifluoroethylamino)ethyl)indol (5) und 1-Methyl-2-trifluoroethyl-1,2,3,4-tetrahydro--carbolin (6). Behandlung von2 mit Lithiumaluminiumhydrid, H₂/Pd auf Aktivkohle und Natriumborhydrid führt jedoch zu Hydroxyspiroindolenin8, Hydroxy-bis(trifluoroacetyl)enaminospiroindolin9 und N-Ethyltryptamin (7). Die Ergebnisse werden diskutiert und die Mechanismen der zu den Produkten4–8 führenden Reaktionen werden vorgestellt.

     

A new heteroannulation method to 2-cyclohexenone,mediated by phosphonate auxiliaries. Synthesis of 4,5,6,7-tetrahydrobenzothiazole derivatives

Summary Dimethyl (1,2-epoxy-3-oxocyclohex-1-yl)phosphonate7, easily available from 2-cyclohexen-1-one, affords the new (tetrahydrobenzothiazolyl)phosphonates10 upon reaction with thiocarboxamides8. This cyclocondensation proceeds with regioselective conjunction of the bisnucleophile8 to carbonyl group and adjacent oxirane carbon of the epoxide precursor. On treatment with alkali the 5,6-dihydro-7(4H)benzothiazolones12 are obtained from compounds10, or from the intermediately formed bicyclic dihydroxy derivatives9. Reaction of the corresponding cyclopentylphosphonate14 with thiobenzamide (8b) yields the cyclopentathiazole derivative15 as a single isomer, the dihydro-thiazole moiety being now annulated regio- andcis-stereoselectively to both oxirane carbons of the epoxyphosphonate.

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Eine neue, durch Phosphonat-Synthone gesteuerte Methode zur Heteroanellierung an 2-Cyclohexenon. Synthese von 4,5,6,7-Tetrahydrobenzthiazol-Derivaten

Zusammenfassung Umsetzung des aus 2-Cyclohexen-1-on leicht zugänglichen (1,2-Epoxy-3-oxocyclohex-1-yl)phosphonats7 mit den Thioamiden8 liefert die neuen (Tetrahydrobenzthiazolyl)phosphonate10. Dabei wird der Thiazolring regioselektiv an Carbonylgruppe und benachbarten Oxirankohlenstoff des Epoxyphosphonats anelliert. Mit Alkali werden sowohl die -Hydroxyphosphonate10 als auch die intermediär gebildeten Dihydroxyverbindungen9 zu den 5,6-Dihydro-7(4H)benzthiazolonen12 gespalten. Im Gegensatz dazu reagiert das Cyclopentylphosphonat14 mit Thiobenzamid8b zu einem Cyclopentathiazol-Derivat15, bei dem der Dihydrothiazolring regioundcis-stereoselektiv mit den beiden früheren Oxiran-Kohlenstoffen verknüpft ist.

     

Darzens reaction as a convenient method for the synthesis of α-chloroketones, α-chloroepoxides,and symmetrically substituted dioxines

Summary TheDarzens reaction of dichloroacetophenone (DCAP) with substituted benzaldehydes has been studied. The structure of the products was shown to depend on the phenyl group substituents. Reaction of benzaldehyde, 4-bromo-, and 2,4-dichlorobenzaldehydes results in 1-phenyl-3-aryl-3-chloropropane-1,2-diones (2a–c), reaction ofpara- ormeta-nitrobenzaldehydes yields 1-phenyl-2-chloro-3-aryl-2,3-epoxypropane-1-ones (3a, b). Upon the introduction of an alkoxy group into the phenyl ring of benzaldexyde and/or dichloroacetophenone, symmetrically substituted dioxines were obtained (6a–c). The structure of the reaction products has been established by single crystal X-ray investigations.

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Darzens-Reaktion als bequemes Verfahren zur Synthese von -Chloroketonen, -Chloroepoxiden und symmetrisch substituierten Dioxinen

Zusammenfassung DieDarzens-Reaction von Dichloracetophenon (DCAP) mit substituierten Benzaldehyden wurde untersucht. Die Struktur der Produkte ist von den Substituenten an der Phenylgruppe abhängig. Die Umsetzung mit Benzaldehyd, 4-Brom- und 2,4-Dichlorbenzaldehyd liefert 1-Phenyl-3-aryl-3-chloropropan-1,2-dione (2a–c), die Reaktion vonpara- odermeta-Nitrobenzaldehyd 1-Phenyl-2-chloro-3-aryl-2,3-epoxipropan-1-one (3a,b). Durch Einführung einer Alkoxygruppe in den Phenylring des Benzaldehyds und/oder des Dichloracetophenons erhält man symmetrisch substituierte Dioxine (6a–c). Die Struktur der Reaktionsprodukte wurde mittels Röntgenstrukturanalyse bestätigt.

     

Synthesis of 2′,3′-dideoxynucleosides from 5-alkoxymethyluracils

Summary A modified synthesis of protected 2,3-dideoxyribose5 starting fromL-glutamic acid (1) is described. Reaction of5 with silylated 5-hydroxymethyluracil7 a and 5-alkoxymethyluracils7 b–e in the presence of trimethylsilyl triflate afforded an anomeric mixture of 2,3-dideoxyuridine derivatives8 a–e and9 a–e. Deprotection with methanolic ammonia and separation by chromatography gave the corresponding nucleosides10 a–e and11 a–e. Treatment of9 b–e with tri(1H-1,2,4-triazol-1-yl)phosphine oxide and subsequent reaction of12 b–e with ammonia in dioxane afforded the cytosine derivatives13 b–e which on treatment with methanolic ammonia gave the corresponding 2,3-dideoxycytidine derivatives14 b–e and15 b–e. In contrast with the parent compounds, these alkoxymethyl derivatives had no appreciable activity against human immunodeficiency virus (HIV-1).

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Synthese von 2,3-Dideoxynucleosiden aus 5-Alkoxymethyluracilen

Zusammenfassung Ausgehend vonL-Glutaminsäure (1) wird eine modifizierte Synthese von geschützter 2,3-Dideoxyribose (5) beschrieben. Reaktion von5 mit silyliertem 5-Alkoxymethyluracilen7 b–e in Gegenwart von Trimethylsilyltriflat ergab anomere Mischungen der 2,3-Dideoxyuridinderivate8 a–e und9 a–e. Abspaltung der Schutzgruppe mit methanolischen Ammoniak und chromatographische Trennung ergab die entsprechenden Nucleoside10 a–e und11 a–e. Behandlung von9 b–e mit Tri(1H-1,2,4-triazol-1-yl)phosphinoxid und nachfolgende Reaktion von12 b–e mit Ammoniak in Dioxan ergab die Cytosinderivate13 b–e, welche nach Behandlung mit methanolischem Ammoniak die entsprechenden 2,3-Dideoxycytidinderivate14 b–e und15 b–e ergaben. Im Gegensatz zur Stammverbindung hatten diese Alkoxymethylderivate keine nennenswerte Wirksamkeit gegen den menschlichen Immunschwächevirus (HIV-1).

     

Synthesis ofD-apio-β-D-furanosyl maleimide, an analogue of showdomycin with transposed hydroxymethyl group

Summary Apioshowdomycin (3-(D-apio--D-furanosyl)-1H-pyrrole-2,5-dione,2) has been prepared as an analogue of the C-nucleoside showdomycin (1) in eight steps and with 5% overall yield, starting from 2,3-O-isopropylidene-D-apio--D-furanose (3).

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Synthese vonD-Apio--D-furanosyl-maleinsäureimid, einem Showdomycinanalogen mit verschobener Hydroxymethylgruppe

Zusammenfassung Ausgehend von 2,3-O-Isopropyliden-D-apio--D-furanose (3) wurde in acht Stufen und 5% Gesamtausbeute Apioshowdomycin (3-(D-Apio--D-furanosyl)-1H-pyrrol-2,5-dion,2), ein Analoges des C-Nucleosids Showdomycin (1), hergestellt.

     

Acetylenchemie, 14. Mitt.: PTC-Umsetzung von 9(10H)-Acridinon mit 3-Chlor-3-phenyl-1-propin und 3-Brom-1-phenyl-1-propin

Summary Reaction of 9(10H)-acridinone (2) with 3-chloro-3-phenyl-1-propyne under PTC conditions affords 1-methyl-2-phenyl-6H-pyrrolo[3,2,1-de]acridin-6-one (1 b), 10-(2-chloro-1-methyl-2-phenyl-ethenyl)-9(10H)-acridinone (4), 10-(3-phenyl-1-propynyl)-9(10H)-acridinone (7), and 10-(4-methylene-2,3-diphenyl-2-cyclobuteneylidenemethyl)-9(10H)-acridinone (5). The structure of the last compound which crystallizes in the triclinic system with the space group , was confirmed by X-ray diffraction. Under the same conditions 10-(3-phenyl-2-propynyl)-9(10H)-acridinone (3) and 10-(3-phenyl-1-propynyl)-9(10H)-acridinone (6) were obtained from 9(10H)-acridinone (2) and 3-bromo-1-phenyl-1-propyne.

     

Über Dihydro-6-methyl- bzw.-6-styryl-4-phenyl-2(1H)-pyrimidinone (-thione) sowie Hexahydro-5-benzoyl- bzw.-cinnamoyl-4,7-diphenyl-2(1H)-chinazolinone (-thione)

Zusammenfassung Dihydro-6-methyl-4-phenyl-2 (1H)-pyrimidinone (-thione) (1) reagieren als -Methylalkenylharnstoffe bzw.-thioharnstoffe mit Säuren zu Hexahydro-4,4-methylendi-2(1H)-pyrimidinonen (-thionen) (3), mit Phenolen zu Tetrahydro-6-hydroxyphenyl-2(1H)-pyrimidinonen (-thionen) (2), mit Benzaldehyd zu 6-Styrylverbindungen (1 d, e, g) und mit ,-ungesättigten Ketonen zu Tetrahydro-2(1H)-chinazolinonen (7). Aus 1,5-Diphenyl-1,4-pentadien-3-on und Harnstoffen, Thioharnstoffen bzw. Ammonrhodanid entstehen Diphenyl-1,3,7,9-tetraazaspiro-5,5-undecan-2,8-dione (9) bzw. Hexahydrotriphenyl-6-cinnamoyl-2(1H)-chinazolinthione (10). Hexahydro-6-benzoyl-bzw.-6-cinnamoyl-2(1H)-chinazolinone (-thione) (10) bilden sich allgemein bei Einwirkung von ,-ungesättigten Ketonen auf Dihydro-4-phenyl-6-styryl-2(1H)-pyrimidinone (-thione) (1 d, e, g).

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Heterocycles, XXVII: Dihydro-6-methyl-(or-6-styryl-)-4-phenyl-2(1H)-pyrimidinones (-thiones); Hexahydro-5-benzoyl-(or-cinnamoyl-)-4,7-diphenyl-2(1H)-quinazolinones (-thiones)

Dihydro-6-methyl-4-phenyl-2(1H)-pyrimidinones (-thiones) (1) react as -methylalkenylureas (-thioureas) with acids to hexahydro-4.4-methylenedi-2(1H)-pyrimidinones (-thiones) (3), with phenols to tetrahydro-6-hydroxyphenyl-2(1H)-pyrimidinones (-thiones) (2), with benzaldehyde to 6-styryl compounds (1 d, e, g) and with ,-unsaturated ketones to tetrahydro-2(1H)-quinazolinones (7).On reacting 1.5-diphenyl-1.4-pentadien-3-one with ureas, thioureas or ammonium thiocyanate, the products formed are diphenyl-1.3.7.9-tetraazaspiro-5.5-undecane-2.8-diones (9) and hexahydrotriphenyl-6-cinnamoyl-2(1H)-quinazolinethiones (10), resp. Hexahydro-6-benzoyl- (or-6-cinnamoyl-)-2(1H)-quinazolinones (-thiones) (10) are formed generally by the action of ,-unsaturated ketones on dihydro-4-phenyl-6-styryl-2(1H)-pyrimidinones (-thiones) (1 d, e, g).

     

Titanocen-cyandithioformiat-Komplexe

The reaction of titanocene dichloride,Cp ₂TiCl₂ (Cp=⁵-C₅H₅), with one or two equivalents of sodium cyanodithioformate affords the new mono- or bis(dithiocarboxylato) derivativesCp ₂TiCl(S₂CCN) (1) andCp ₂Ti(S₂CCN)₂ (2). Elimination of sulfur converts2 into the metallacyclicCp ₂TiS₂C₂(CN)₂ (3), which does not react with the diene isoprene, but can be reconverted into the appropriate titanocene dihalides by chlorine or bromine.

     

Formation of new 4-isocyanobut-2-enenitriles by thermal ring cleavage of 3-pyridyl azides

A new thermal ring cleavage of 3-pyridyl nitrenes for the formation of 4-isocyanobut-2-enenitrile products is reported. Thermolysis of 4-(thien-3-yl)-3-pyridyl azide 1 and 3-azido-4-(1-TIPS-1H-pyrrol-3-yl)pyridine 5 afforded two new isonitrile-nitrile products by ring cleavage; 4-isocyano-2-(thiophen-3-yl)but-2-enenitrile (3, 27%) and 4-isocyano-2-(1-TIPS-1H-pyrrol-3-yl)but-2-enenitrile (7, 20%), in addition to our previously reported pyrido[3,4-b]thienopyrrole (2, 29%) and pyrido[3,4-b]pyrrolo[3,2-d]pyrrole (6, 71%) products. Minor amounts of 2-(thien-3-yl)-1H-pyrrole-3-carbonitrile (4, 6%), formed by ring contraction, were also isolated after thermolysis of azide 1. Isonitriles 3 and 7 underwent degradation into amine 3b and formamide 7a by acidic hydrolysis. The nature and chemistry of compounds 3, 4 and 7 were investigated.