1,3-Diphenylbenzo[e][1,2,4]triazin-7(1H)-one: selected chemistry at the C-6, C-7 and C-8 positions

1,3-Diphenylbenzo[e][1,2,4]triazin-7(1H)-one (6) reacts with tetracyanoethylene (TCNE) or tetracyanoethylene oxide (TCNEO) to give the deep green 2-[1,3-diphenylbenzo[e][1,2,4]triazin-7(1H)-ylidene]propanedinitrile (11) in 17 and 15% yields, respectively. Nucleophiles such as amines, alkoxides, thiols and Grignard reagents all reacted with the 1,3-diphenylbenzotriazinone 6 regioselectively at C-6, while halogenating agents reacted exclusively at C-8. Furthermore, 8-iodo-1,3-diphenylbenzo[e][1,2,4]triazin-7(1H)-one (32) undergoes palladium-catalysed Suzuki-Miyaura and Stille coupling reactions to give 8-aryl- or heteroaryl-substituted benzotriazinones. By combining both the C-6 and C-8 chemistries 1,3,6,8-tetraphenylbenzo[e][1,2,4]triazin-7(1H)-one (42) and 1,3-diphenyl-6,8-di(thien-2-yl)-benzo[e][1,2,4]triazin-7(1H)-one (43) can be prepared. All new compounds are fully characterized.     

Diisophorone and related compounds—II: 1-Alkoxy- and 1-carboxy-diisophorane derivatives

The acid catalysed interaction in dioxan of trialkyl orthoformates with diisophor-2(7)-en-ol-3-one, diisophor-2(7)-en-ol, and their bisnor-homologues, provides the corresponding 1-alkoxy-compounds. Their structure is established by the identity of -methoxydiisophor-2(7)-en-3-one obtained by this method, and by the action of sodium methoxide on 1-chlorodiisophor-2(17)-en-3-one. The latter is regenerated from 1-methoxy(or ethoxy) diisophor-2(7)-en-3-one by the action of stannic chloride-acetyl chloride. Catalytic hydrogenation reduces the 3-keto-function in 1-alkoxydiisophor-2(7)-en-3-ones to a methylene unit; simultaneous removal of the 1-alkoxy-group in the case of the 1-isopropoxy-homologue yields the penultimate parent hydrocarbon of this series, diisophor-2(7)-ene.The combined action of silver sulphate and formic acid in concentrated sulphuric acid on 1-chlorodiisophor-2(7)-en-3-one (and its bisnor-homologue) produces the corresponding 1-carboxylic acids. These are also obtainable by the hydrolysis of the 1-cyano-compound, and are esterifiable by the standard methods.     

Synthesis of 11-hydroxydrim-8(9)-en-7-one and 11,12-dihydroxydrim-8(9)-en-7-one from drim-8(9)-en-7-one

A synthetic route to 11-hydroxydrim-8(9)-en-7-one and 11,12-hydroxydrim-8(9)-en-7-one, valuable key intermediates for the preparation of naturally occurring biologically active drimanic sesquiterpenoids, starting from easily available drim-8(9)-en-7-one was developed. 11-Hydroxydrim-8(9)-en-7-one was obtained by peracidic oxidation of the enol acetate of drim-8(9)-en-7-one. 11,12-Dihydroxydrim-8(9)-en-7-one was synthesized from drim-8(9)-en-7-one by two routes, namely, by a five-step procedurevia 11-hydroxydrim-8(9)-en-7-one and by bromination of drim-8(9)-en-7-one with NBS to give 11,12-dibromodrim-8(9)-en-7-one followed by its acetoxylation and deacetylation. Deceased Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 95–98, January, 2000.     

Synthesis of 11-hydroxydrim-8(9)-en-7-one and 11,12-dihydroxydrim-8(9)-en-7-one from drim-8(9)-en-7-one

A synthetic route to 11-hydroxydrim-8(9)-en-7-one and 11,12-hydroxydrim-8(9)-en-7-one, valuable key intermediates for the preparation of naturally occurring biologically active drimanic sesquiterpenoids, starting from easily available drim-8(9)-en-7-one was developed. 11-Hydroxydrim-8(9)-en-7-one was obtained by peracidic oxidation of the enol acetate of drim-8(9)-en-7-one. 11,12-Dihydroxydrim-8(9)-en-7-one was synthesized from drim-8(9)-en-7-one by two routes, namely, by a five-step procedurevia 11-hydroxydrim-8(9)-en-7-one and by bromination of drim-8(9)-en-7-one with NBS to give 11,12-dibromodrim-8(9)-en-7-one followed by its acetoxylation and deacetylation. Deceased Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 1, pp. 95–98, January, 2000.     

Design and synthesis of novel tricycles based on 4H-benzo[1,4]thiazin-3-one and 1,1-dioxo-1,4-dihydro-2H-1lambda6-benzo[1,4]thiazin-3-one

This paper reports our recent efforts to develop novel tricycles based on 4H-benzo[1,4]thiazin-3-one ( 2) and 1,1-dioxo-1,4-dihydro-2H-1lambda(6)-benzo[1,4]thiazin-3-one (3) using 1,5-difluoro-2,4-dinitrobenzene (1). All of these tricycles integrate two privileged structures into one skeleton, including 3,8-dihydro-5-thia-1,3,8-triaza-cyclopenta[b]naphthalene-7-one (4, 10, 12), 5,5-dioxo-3,5,6,8-tetrahydro-5lambda(6)-thia-1,3,8-triaza-cyclopenta[b]naphthalene-7-one (5, 11), 3,8-dihydro-5-thia-1,2,3,8-tetraaza-cyclopenta[b]naphthalene-7-one (6), 5,5-dioxo-3,5,6,8-tetrahydro-5lambda(6)-thia-1,2,3,8-tetraaza-cyclopenta[b]naphthalene-7-one (7), 3,8-dihydro-1H-5-thia-1,3,8-triaza-cyclopenta[b]naphthalene-2,7-dione (8), and 5,5-dioxo-3,5,6,8-tetrahydro-1H-5lambda(6)-thia-1,3,8-triaza-cyclopenta[b]naphthalene-2,7-dione (9). A typical library of scaffold 5 was synthesized in a parallel solution-phase manner and analyzed by HPLC-UV-MS or HPLC-UV-ELSD method.     

Synthesis of a 4-hydroxyisoquinolin-1-one and a related dibenzo[α,g]quinolizin-8-one

Aqueous acid converts the imidazo[4,3-α]isoindol-5-one 2 to a 4-hydroxyisoquinolin-1-one ( 3 ). A related imidazoisoindolone 6 , obtained by photochemical cyclization of the Mannich base from 1,2,3,4-tetrahydro-isoquinoline, formaldehyde and phthalimide, gives a dibenzo[a,g]quinolizin-8-one ( 7 ) in a similar reaction.     

Mass spectra of 3,3-difluoro-1-halo-2-arylcyclopropenes

The electron ionization (EI) mass spectra of a series of 3,3-difluoro-1-halo-2-arylcyclo- propenes (1, 2) give the fragments [M-X](+) (X: Br, Cl) as the base peaks. A comparison of tandem mass spectrometry (MS/MS) profiles of the m/z 151 ions recorded from compounds 1 and 2 and 3-bromo-3,3-difluoro-1-phenylcyclopropyne (5), 1,1,2,2-tetrafluoro-3-phenyl- cyclopropane (6), 1,1,2,2-tetrafluoroindane (7), and 2,3,3-trifluoroindene (8) suggested that the structure of the derived [M-X](+) fragment ion is more likely that of a substituted cyclopropenium ion. The results from calculations using the density functional theory (DFT) method support this MS/MS analysis.     

Behaviour of 2-subst1tuted 6,8-dibromo-3,1-benzoxazin-4-ones towards o-phenylenediamine and anthranilic acid ; a case of unusual cleavage of 6,8-d1bromo-2-methyl-3,1-benzoxazin-4-one

6,8-Dibromo-2-methyl-3,l-benzoxazin-4-one (1) reacts with o-phenylenediamine to give a mixture of 3,5-dibromoanthranilic acid (2), 2-methylbenzimidazole (3) and 3-(o-aminophenyl)-6,8-dibromo-2-methylquinazolin-4-one (4). However, when the reaction was conducted in ethanol or in the absence of solvent at elevated temperature, a mixture of (2) & (3) was obtained. A similar cleavage of (1) took place when it was allowed to react with anthranilic acid yielding a mixture of (2) and N-acetylanthranilic acid (6). The reaction of o-phenylenediamine with 6,8-dibromo-2-phenyl-3,1-benzoxazin-4-one (7) proceeded normally to give 3-(o-aminophenyl)6,8-dibromo-2-phenylquinazolin-4-one (8) or 2-benzoyl-amino-3, 5-dibromo-N-(o-aminophenyl)benzamide (9), depending upon the reaction conditions.     

Organocatalytic entry to chiral bicyclo[3.n.1]alkanones via direct asymmetric intramolecular aldolization

[reaction: see text] The facile stereoselective syntheses of endo-8-hydroxybicyclo[3.3.1]nonan-2-one and endo-7-hydroxybicyclo[3.2.1]octan-2-one, featuring an alpha-amino acid catalyzed intramolecular aldolization of sigma-symmetric substrates, are described. A high enantioselectivity and a high catalytic efficiency have been exhibited by (4R,2S)-tetrabutylammonium 4-TBDPSoxy-prolinate in the aldolization of 3-(4-oxocyclohexyl)propionaldehyde to give highly enantiomerically enriched (1S,5R,8R)-8-hydroxybicyclo[3.3.1]nonan-2-one.     

Cyclization reactions of 1,3-dibromopropan-2-ol, 2,3-dibromopropan-1-ol and 1-bromomethyloxirane with 6-amino-2,3-dihydro-2-thioxo-4(1H)-pyrimidinone

The cyclization reactions, carried out in strongly- or weakly-basic media, are described. Sometimes, 7-amino-2,3-dihydro-3-hydroxymethyl-5H-thiazolo[3,2-a]pyrimidin-5-one is separated out, together with 8-amino-3,4-dihydro-3-hydroxy-2H,6H-pyrimido[2,1-b][1,3]thiazin-6-one, as the principal product. A mechanism of reaction, during which the cyclizating agents are changed into oxirane derivatives, is proposed. The results of single-crystal X-ray investigations on 8-amino-3,4-dihydro-3-hydroxy-7-nitroso-2H,6H-pyrimido[2,1-b][1,3]thiazin-6-one (R = 0.035 for 1013 reflections), and on 7-hydroxymethyl-6,7-dihydrothiazolo[3,2-a][1,2,3]triazolo[4,5-d]pyrimidin-9(1H)-one (R = 0.027 for 1607 reflections) are reported.     

Reaction of 1-chloromethyl-4,5-dichloropyridazin-6-one

Reaction of 1-chloromethyl-4,5-dichloropyridazin-6-one with some nucleophiles such as sodium methoxide, sodium azide, 2-mercaptopyrimidine and phenol gave 2, 3, 4, 7, 8 and 10 . 5-Chloro-4-phenoxypyridazin-6-one ( 10 ) was also synthesized from 8 through 9.     

A study of the Claisen rearrangement of 7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one derivatives

Summary The Claisen rearrangement of 7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one (2 a) gave 7-hydroxy-8-(1-phenyl-2-propenyl)-3-phenyl-(4H)-1-benzopyran-4-one (3 a) and 2,3-dihydro-2,6-diphenyl-3-methyl-(7H)furo[2,3-h]-1-benzopyran-7-one (7 a). 2-Methyl-7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one (2 b) afforded4 b and7 b. 8-Methyl-7-(3-phenyl-2-propenyloxy)-3-phenyl-(4H)-1-benzopyran-4-one (12) gave only the alkali soluble product 7-hydroxy-8-methyl-6-(1-phenyl-2-propenyl)-3-phenyl-(4H)-1-benzopyran-4-one (13).3 a,4 b, and13 were further cyclized in acidic medium to9 a,10 b, and14 followed by dehydrogenation.This paper is dedicated to Dr. F. M. Dean, Department of Organic Chemistry, Robert Robinson Laboratories, University of Liverpool, Liverpool, U. K., on his retirement     

2,2′-Bifurylidene-5,5′-diones,Coumarins, 3a, 7a-dihydro-1H-inden-1-ones,and 5H-furo[3,2-b]pyran-5-ones from propyne and carbon monoxide

The [Co₂ (CO)₈]-catalyzed reaction between propyne and CO in acetone at 110° and 170 bar was re-investigated. There are five major products: (E)-3,4′-dimethyl-2,2′-bifurylidene-5,5′-dione ( 4 ), 3,5,8-trimethylcoumarin ( 8 ), 3a, 7a-dihydro-2,4,7,7a-tetramethyl-1H-inden-1-one ( 9 ), 2,6-dimethyl-5H-furo [3,2, -b]- pyran-5-one ( 11 ), and 2,7-dimethyl-5H-furo 3,2-b-pyran-5-one ( 12 ); of these, only one, 4 . had previously been recognized. In parallel experiments were obtained 2,6-dipentyl-5 H-furo[3,2-b]pyran-5-one ( 13 ), 2,7-dipentyl–5H-furo[3,2-b]pyran-5-one ( 14 ), 3a, 7a-dihydro-2,4,7,7a-tetrapentyl-1H-inden-1-one ( 15 ). And 3a, 7a-dihydro-2,4,6,7a-tetrapentyl-1H-inden-1-one ( 16 ) from hept-1-yne, and two further types of products from two atypical 1-alkynes: 3,6,9-tri(tert-butyl)-1-oxaspiro[4.4]nona-3,6,8-trien-2-one ( 20 ) from (tert-butyl)acetylene and the exo-dimer 21 of 2,5-bis(trimethylsilyl)cyclopenta-2,4-dien-1-one ( 22 ) from (trimethylsilyl)acetylene. Compounds 11,12 , and 20 were identified by X-ray analysis.     

Reactions of 1-halo-3-methyl-2,3-epoxybutane with alcohols

The reaction of 1-bromo(or chloro)-3-methyl-2,3-epoxybutane with alcohols in the presence of the alkali metal alkoxides leads to the formation of epoxy ethers by direct replacement of the halogen atoms without participation of the epoxide ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 878–880, July, 1981.     

Synthesis of 1H-pyrazolo[3,4-c]isoquinolin-1-ones by the condensation of cyclohexanone derivatives with 3-amino-1-phenyl-1H-pyrazol-5(4H)-one

The synthesis of 1H-pyrazolo[3,4-c]isoquinolin-1-ones was carried out by reacting 3-aryl(heteryl)-2,4-diacetyl-5-hydroxy-5-methylcyclohexanones with 3-amino-1-phenyl-1H-pyrazol-5(4H)-one. The structure of the 7-acetyl-2,4,6,7,8,9-hexahydro-8-hydroxy-5,8-dimethyl-2-phenyl-6-(fur-2-yl)-1H-pyrazolo[3,4-c]isoquinolin-1-one obtained was proved by X-ray diffraction analysis.     

Synthesis Of 1-Benzazepines as Precursors of 1-Benzazepinediones

The synthesis of 6-hydroxy-7-nitro-1-benzazepine-2-one 7 from 5-hydroxy-1-tetralone 1 and 6-hydroxy-1-benzazepine-2-one 2 is described. Bromination of 6-hydroxy-1-benzazepine-2-one 2 with NBS in ethyl acetate afforded 7-bromo-6-hydroxy-1-benzazepine-2-one 13 and 7,9-dibromo-6-hydroxy-1-benzazepine-2-one 14. Oxidation of benzazepinone 13 with (diacetoxyiodo)benzene provided 7-bromo-1-benzazepine-2,6,9-trione 5.     

3-Methylpyrazolo [1,2-a] pyridazin-1-one. Selenium derivatives of 5,8-dihydropyrazolo[1,2-a]pyridazine

The dehydrogenation of the known 3-methyl-5,8-dihydropyrazolo[1,2-a]pyridazin-1-one (2) to the ten π electron heteroaromatic 3-methylpyrazolo[1,2-a]pyridazin-1-one ( 3 ) is reported. Conversions of the pyrazolone 2 to the pyrazoloselenone 6 via the chloropyrazolium chloride 7 , and of pyrazolones 2 and 3 and pyrazoloselenone 6 into the corresponding O or Se ethyl pyrazolium fluoroborates 5, 4 , and 8 by triethyloxonium fluoroborate are also described.     

Biotransformation of (1S)-2-carene and (1S)-3-carene by Picea abies suspension culture

Biotransformation of (1S)-2-carene and (1S)-3-carene by Picea abies suspension culture led to the formation of oxygenated products. (1S)-2-Carene was transformed slowly and the final product was identified as (1S)-2-caren-4-one. On the other hand, the transformation of (1S)-3-carene was rapid and finally led to the formation of (1S)-3-caren-5-one and (1S)-2-caren-4-one as equally abundant major products. The time-course of the reaction indicates that some products abundant at the beginning of the reaction (e.g. (1S, 3S, 4R)-3,4-epoxycarane and (1R)-p-mentha-1(7),2-dien-8-ol) were consumed by a subsequent transformations. Thus, a precise selection of the biotransformation time may be used for a production of specific compounds.     

Synthesis and total assignment of 1H and 13C NMR spectra of new oxoisoaporphines by long-range heteronuclear correlations

The new oxoisoaporphines 7H-dibenzo[de,h]quinolin-7-one, 5-methoxy-7H-dibenzo[de,h]quinolin-7-one, 5-methoxy-6-hydroxy-7H-dibenzo[de,h]quinolin-7-one, 5-hydroxy-7H-dibenzo[de,h]quinolin-7-one and 5-methoxy-6H-dibenzo[de,h]quinolin-6-one were prepared either by oxidation of their 2,3-dihydro derivatives or by heating (2'-(3,4-dihydro-6,7-dimethoxyisoquinolin-1'-yl)phenyl)methylbenzoate with an acetic acid/sulfuric acid mixture at 100 degrees C. The structures were confirmed and 1H and 13C NMR spectra were completely assigned using two-dimensional NMR techniques.     

A new ring transformation of 3-halo-2-azidopyridine 1-oxides. A novel synthesis of 1,2-oxazin-6-ones

The course of the thermal ring-opening and recyclization of 2-azidopyridine 1-oxides is radically altered by the presence of a 3-halo substituent. Provided the 6-position is blocked, recyclization leads to a 6-cyano-6-halo-1,2-oxazine which hydrolyzes very readily to the 6H-1,2-oxazin-6-one. The structure of 4-bromo-3-methyl-6H-1,2-oxazin-6-one so obtained was confirmed by single crystal X-ray analysis. If the 6-position is not blocked, the product undergoes a further ring opening to give (Z)-β-cyanoacrylates.