bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electron bombardment induced fragmentation of substituted oxathiolanes
Authors: Pasto Daniel J. 
Published: March 2009

AbstractThe mass spectral fragmentation patterns of 1,3‐oxathiolane and 2‐, 4‐, and 5‐substituted oxathiolanes have been recorded. The various fragments have been identified by high‐resolution mass spectrometry when appropriate. Of the five possible modes of ring cleavage to produce two‐ and three‐atom fragments only two modes are actually observed. The mode of fragmentation of the 1,3‐oxathiolane ring differs from that proposed for 1,3‐dioxalane and in all probability occurs in multistep processes.
Benzodifurans. I. The synthesis of benzo[1,2‐b:5,4‐b]difuran and some methyl analogs
Authors: Worden Leonard R. , Burgstahler Albert W. , Kaufman Kurt D. , Weis James A. , Schaaf Thomas K. 
Published: March 2009

AbstractThe first parent benzodifuran (XVI) and three di‐ and trimethylated derivatives have been synthesized and screened for erythemal activity (negative response). Two benzodifurans were prepared from resorcinol and 2‐methylresorcinol by acetylation, Fries rearrangement, alkylation of the resulting 4,6‐diacetylresorcinols with ethyl bromoacetate, saponification, and then cyclization of the (4,6‐diacetyl‐1,3‐phenylenedioxy)diacetic acids. Another was prepared from the Claisen rearrangement product of 1,3‐bis(allyloxy)‐2‐methylbenzene by acetylation, bromina‐tion, and cyclization. Ozonolysis of the Claisen rearrangement product gave additional support to the formulation of o‐hydroxyphenylaeetaldehydes as cyclic hemiacetals. The parent benzodifuran was synthesized from 5‐formyI‐6‐hydroxybenzofuran, which was prepared in two steps from 5‐bromo‐6‐methoxybenzofuran. Alkylation of the former with ethyl bromoacetate, saponification, and cyclization furnished benzo[1,2‐b.5,4‐b ]difuran. The ultraviolet and nuclear magnetic resonance spectra of the four benzodifurans are compared.
On 1,2‐benzisoxazole‐3‐acetic acid and 3‐methyl‐1,2‐benzisoxazole: a restatement
Authors: Casini Giovanni , Guallieri Fulvio , Stein Maria L. 
Published: March 2009

AbstractA compound formulated in the literature as 4‐hydroxylaminocoumarin is now recognized to be the isomeric 1,2‐benzisoxazole‐3‐acetic acid. Therefore, a preceding paper by the authors describing this acid is proved incorrect due to inexact data in the previous literature on the preparation of 3‐methyl‐1,2‐benzisoxazole.
Diazepines. VI. The chemistry of 3,8‐dihalo‐11H‐dibenzo[c,f] [1,2]diazepin‐11‐ones
Authors: Popp Frank D. , Dubois Ronald J. , Casey Adria Catala 
Published: March 2009

AbstractThe carbonyl group in the title compounds undergoes a number of reactions typical of ketones but in general is less reactive than a typical ketone. Reaction with hydrazine leads to reduction of the 5,6‐bond rather than reaction at the carbonyl group. Reduction of the carbonyl group gives rise to a rather inert carbinol. The carbonyl group appears to exert little influence on typical reactions at the 5,6‐position.
Proton magnetic resonance studies of compounds with bridgehead nitrogen atoms. IX Configurational and conformational studies with methyl‐substituted 8‐phenyl‐l,8‐diazabicyclo[4.3.0]nonanes
Authors: Crabb T. A. , Newton R. F. 
Published: March 2009

AbstractThe synthesis of a series of methyl‐substituted 8‐phenyl‐1,8‐diazabicyclo[4.3.0]nonanes is described. The preferred conformations of these compounds have been assigned on the basis of the 2850‐2500 cm−1 region of their infrared spectra and of the geminal coupling constant of the C‐9 methylene group.
Chemical and nuclear magnetic resonance studies of 3,3‐diphenyltetrahydrofuran derivatives
Authors: Portoghese P. S. , Williams D. A. 
Published: March 2009

AbstractPyrolytic cyclization of a‐ and β‐methadol methiodides afforded cis and trans isomers of 2‐ethyl‐3,3‐diphenyl‐5‐methyltetrahydrofuran, respectively. Catalytic hydrogenation of 2‐ethyli‐dene‐3,3‐diphenyl‐5‐methyltetrahydrofuran yielded the cis and trans isomers in a 2:1 ratio. The nmr spectra of these and structurally related compounds have been analyzed in terms of a half‐chair conformation for 2‐ethyl‐5‐methyl, 2‐ethyl, and 5‐methyl derivatives. An envelope conformation has been suggested for the compounds containing a double bond at C‐2.
N‐Oxides and S‐oxides of ellipticine analogs
Authors: Fujiwara Allan N. , Acton Edward M. , Goodman Leon 
Published: March 2009

AbstractOxidation with perbenzoic acid derivatives in neutral organic solvents of 11‐desmethylellipticine (at the pyrido‐N) and oxa‐ellipticine afforded the corresponding N‐Oxides. Thia‐ellipticine afforded the sulfone N‐oxide, which underwent N‐deoxygenation with triphenylphosphine to yield thia‐ellipticine sulfone.
Electrophilic substitution reactions in 4H‐benzo[d,e,f]carbazole
Authors: Hoellinger H. , Buu‐Hoï N. P. , Mabille Ph. 
Published: March 2009

AbstractThe behavior of 4H‐benzo[d,e,f]earbazole and its N‐aeetyl derivative in various electrophilic substitution reactions (e.g. nitration, nitrosation, bromination, Friedel‐Crafts acylations) has been investigated, and a number of new derivatives of this heterocycle (some of which are to be tested as potential carcinogens and enzyme‐inducers) have been synthesized.
Studies on the syntheses of heterocyclic compounds. Part CCCXV erythrinan and related compounds. II . An alternative synthesis of cis‐16‐hydroxy‐15‐methoxyerythrinan‐8‐one and its mass spectrum
Authors: Kametani T. , Agui H. , Saito K. , Fukumoto K. 
Published: March 2009

AbstractPhenolic cyclization of 2‐ethoxycarbonylmethylidenecyclohexanone (IV) with 3‐hydroxy‐4‐methoxyphenethylamine (V) were performed in the process of finding a synthetic approach to dihydroerysolidine (I). Thus, 16‐hydroxy‐15‐methoxyerythrinan‐6‐ene‐8‐one (VI) and 16‐hydroxy‐15‐methoxyerythrinan‐7‐ene‐8‐one (VII) were synthesized, both of which were hydrogenated in the presence of Adams platinum to give the same product (XI). Furthermore, on the basis of the mass spectra of XI and XII, these compounds were assumed to be stereoisomeric at the C5‐ and C6‐positions.
Synthesis of phthalimidines. Acid‐catalyzed cyclodehydration versus cyclodeamination of γ‐hydroxyamides obtained from dilithio‐N‐substituted benzamides and ketones
Authors: Mao Chung‐Ling , Barnish I. T. , Hauser Charles R. 
Published: March 2009

AbstractAn earlier method of preparation of γ‐hydroxyamides from N‐substituted benzamides and ketones or aldehydes by means of n‐butyllithium was improved and extended. The γ‐hydroxyamides were found to undergo cyclodehydration to form γ‐lactams with relatively strong acids, but cyclodeamination formed γ‐lactones with relatively weak acids; the γ‐lactams are substituted phthalimidines. The predominant course of cyclization was dependent also on the structure of the γ‐hydroxyamide. Certain γ‐hydroxyamides afforded phthalimidines with cold, concentrated sulfuric acid whereas certain others yielded γ‐lactones with this acid. The latter γ‐hydroxyamides, however, produced phthalimidines with the stronger acid, perchloric acid. The cyclodehydration reaction furnished a convenient and, apparently, quite general method for the synthesis of 2,3,3‐trisubstituted or 2,3‐disubstituted phthalimidines. Mechanisms are considered.
Photo‐elimination of nitrogen from fused‐ring triazoles
Authors: Boyer J. H. , Selvarajan R. 
Published: March 2009

AbstractBy irradiation in methanol at 3000Å, aniline and o‐anisidine were produced from benzo‐triazole and N‐methylaniline and N‐methyl‐o‐anisidine were produced from N‐methylbenzotriazole. Carbazole was the only product detected from similar treatment of N‐phenylbenzotriazole. Linear naphthotriazole was photolytically transformed into β‐naphthylamine but a methoxy derivative could not be found. Angular naphthotriazole gave no identifiable photolytic product. u‐Triazolo[1,5‐α]pyridine underwent photolysis in methanol to give α‐picoline, α‐picolylmethyl ether and α‐picolylmethanol in low yield. A similar photolysis in acetic acid afforded α‐pyridylmethyl acetate. The mechanisms for the formations of products are discussed.
Synthesis of 2,7‐disubstituted‐4,5,9,10‐tetraazapyrenes
Authors: Castle Raymond N. , Guither William D. , Hilbert Peter , Kempter Fritz E. , Patel Natu R. 
Published: March 2009

Abstract2,7‐Dimethyl‐4,5,9,10‐tetraazapyrene (VI) was synthesized by the catalytic hydrogenation of 4,4′‐dimethyl‐2,2′,6,6′‐tetranitrobiphenyl (IIa) with W‐2 Raney nickel in the presence of alkali. 4,4′‐Dicarbomethoxy‐2,2′,6,6′‐tetranitrobiphenyl (IIc) under similar conditions in neutral medium gave 4,4′‐dicarbomethoxy‐2,2′,6,6′‐tetraaminobiphenyl (IV) which on oxidation gave 2,7‐dicarbomethoxy‐4,5,9,10‐tetraazapyrene (V). 2,7‐Dimethyl‐, 2,7‐dimethoxy‐, and 2,7‐diacetamido‐4,5,9,10‐tetraazapyrene di‐N‐oxides (III a,b,c) were obtained by catalytic reduction of the corresponding 4,4′‐disubstituted‐2,2′,6,6′‐tetranitrobiphenyls with W‐7 Raney nickel in the presence of alkali. Compound VI on oxidation with hydrogen peroxide gave the di‐N‐oxide (IIIa).
Pinacol rearrangement of quinoline analogs of benzopinacol and evidence for rearrangement under the conditions of electron impact
Authors: Brown Ellis V. , Frazer Marshall G. 
Published: March 2009

AbstractThe pinacols, 1,2‐di(2‐quinolyl)‐1,2‐diphenylethane‐1,2‐diol and 1,2‐di(8‐quinolyl)‐1,2‐diphenylethane‐1,2‐diol, were prepared and rearranged. The mass spectrum of the phenyl‐2‐quinolylpinacolone showed fragment peaks corresponding to the pinacolone resulting from 2‐quinolyl migration. The mass spectrum of the phenyl‐8‐quinolylpinacolone showed fragment peaks corresponding to the pinacolone resulting from phenyl migration. Evidence for the rearrangement by electron impact was observed in the mass spectrum of each pinacol.
Ring closure reactions with nitriles. III. Formation of 2‐amino‐ and 2‐oxo‐3‐hydroxyindoles from the reaction of 2′‐aroylacylanilides with cyanide
Authors: Bell Stanley C. , Wei Peter H. L. 
Published: March 2009

AbstractTreatment of 2′‐aroylhaloacylanilides with potassium cyanide produced quinazolines, carbostyrils, and 3‐hydroxyindoles. From the reaction of 2′‐aroyl‐2,2‐dichloroacetanilides with cyanide, good yields of 2‐amino‐3‐hydroxyindoles were obtained and their reactions were studied.
Synthesis of 2,4‐diamino‐9H‐indeno[2,1‐d]pyrimidines
Authors: Rosowsky Andre , Dey Adrienne S. , Battaglia Josephine , Modest Edward J. 
Published: March 2009

AbstractAs part of a search for new antifolic, antimalarial, and antitumor agents, a series of 2,4‐diamino‐9H‐indeno[2,1‐d]pyrimidines was prepared by condensation of guanidine with substituted 2‐alkoxy‐3‐cyano‐1H‐indenes. Base‐catalyzed cyclization of 1,2‐bis(cyanomethyl)benzenes afforded 2‐amino‐3‐cyano‐1H‐indenes, which were converted into 3‐cyano‐2‐methoxy‐1H‐indenes by acid hydrolysis and treatment of the resultant 1‐cyano‐2‐indanones with diazomethane. Alternatively, 2‐amino‐3‐cyano‐1H‐indenes could be transformed directly into 2‐ethoxy‐3‐eyano‐1H‐indenes by reaction with ethanol and sulfuric acid. The 2,4‐diamino‐9H‐indeno[2,1‐d]‐pyrimidines represent a new type of planar, tricyclic pyrimethamine analog, in which free rotation of the phenyl and pyrimidine rings is prevented by means of a methylene bridge.
Nucleoside analogs. I. A synthesis of 1,3‐dihydroxy‐2‐(6‐substituted‐9‐purinyl)cyclohexane
Authors: Suami Tetsuo , Sato Yutaka , Fukai Yasushi , Sakota Yukio 
Published: March 2009

AbstractBiologically active 1,3‐dihydroxy‐2‐(6‐substituted‐9‐purinyl)cyclohexanes (VI‐X) were prepared by a reaction between trans‐2‐amino‐1,3‐cyclohexanediol (I) and 4,6‐dichloro‐5‐amino‐pyrimidine (II), followed by cyclization and nucleophilic substitution.Compounds VI and VII showed a weak inhibitory effect against Xanthomonas oryzae, a pathogenic bacteria of leaf blight of rice plant.
Synthesis and interconversion of 6‐aroyl‐4‐oxohexanoie acids and 5‐aryl‐2‐furanpropionic acids. Antiinflammatory agents
Authors: Short Franklin W. , Rockwood Gail M. 
Published: March 2009

AbstractA series of 6‐aroyl‐4‐oxohexanoic acids (2) was prepared for intermediate use by acid‐catalyzed solvolysis of substituted 3‐(2‐furyl)acrylophenones (1). This reaction occasionally gave 5‐aryl‐2‐furanpropionic acids (3) instead of, or in addition to, the desired diketones (2). Equilibrium between 2 and 3 was observed in the case where Ar is m‐nitrophenyl. A rationalization for the formation of 3 is offered, and published reports with which our results differ are discussed. Diketones (2) were cyclized to furans (3) and antiinflammatory screening data are reported for the latter.
Aminolysis of 1,2,3‐benzotriazin‐4(3H)‐thione
Authors: Gilbert Everett E. , Veldhuis B. 
Published: March 2009

AbstractA series of 4‐N‐substituted 1,2,3‐benzotriazin‐4(3H)‐imines was prepared by aminolysis of 1,2,3‐benzotriazine‐4(3H)‐thione and its 6‐chloro derivative with primary aliphatic amines. The reaction was shown to be sensitive to amine structure and to reaction conditions. Frequently observed tar formation is attributed to instability resulting from the cryptodiazonium character of the triazine ring. Spectral data substantiate the thiono and imino structures of the starting compounds and products, respectively, in the solid state.
Mass spectral study on thiazolo[3,2‐a]benzimidazoles. Studies on heterocyclic compounds. IV
Authors: Ogura H. , Itoh T. , Kikuchi K. 
Published: March 2009

AbstractCondensation of α‐halocarbonyl compounds and 2‐mercaptobenzimidazole gives thiazolo‐[3,2‐a]benzimidazoles. This condensation occurred at the mercapto group of the benzimidazole followed by cyclization to form the thiazole ring. This was confirmed by the examination of the mass spectra of 2‐ and 3‐methylthiazolo[3,2‐a]benzimidazoles, 2‐ and 3‐phenylthiazolo[3,2‐a]‐benzimidazoles, and their derivatives.
Chloro‐ and dichloro‐3‐alkyl‐1,2,3‐benzotriazin‐4(3H)ones
Authors: Gilmore W. Franklin , Clark Robert N. 
Published: March 2009

AbstractSeveral chloro‐ and dichloro‐3‐alkyl‐1,2,3‐benzotriazin‐4(3H)ones have been prepared by diazotization of methyl anthranilates. A brief study was made of factors affecting the formation of 3‐allyl‐1,2,3‐benzotriazin‐4(3H)one from methyl anthranilate. Good nmr evidence was obtained to substantiate the previously proposed methyl 2‐(3‐allyltriazeno)benzoate (VIc) intermediate.
Friedel‐crafts cyclisations. II. Further studies of polyphosphoric acid‐catalysed cyclisations of N‐cinnamoyl derivatives of aromatic amines
Authors: Johnston K. M. 
Published: March 2009

AbstractFurther studies of the effects of substituents in the N‐phenyl nucleus on the polyphosphoric acid‐catalysed cyclisation of cinnamanilide to 4‐phenyl‐3,4‐dihydrocarbostyril have confirmed that the isomerisation is prevented by a nitro group and retarded by other substituents in the ortho position to the NH‐ group. Although a methyl group ortho to the only position at which cyclisation can occur was also shown to retard the reaction, N‐cinnamoyl‐2,4,5‐trichloroaniline was cyclised in moderate yield after prolonged heating, but the 2,4‐dibromo and 2,5‐dimethoxy analogues were not isomerised.Isomerisation of 2‐cinnamamidobiphenyl to 4,8‐diphenyl‐3,4‐dihydrocarbostyril was accompanied by cyclodehydration to 6‐styrylphenanthridine. Five new derivatives of cinnamanilide and eight new derivatives of 4‐phenyl‐3,4‐dihydrocarbostyril are described.
Crystal and molecular structure of 3‐hydroxy‐5‐phenylisoxazole (α form)
Authors: Biagini S. , Cannas M. , Marongiu G. 
Published: March 2009

AbstractThe crystal structure of the α form of 3‐hydroxy‐5‐phenylisoxazole has been determined from three‐dimensional X‐ray data. The crystals are monoclinic, space group P21/n with four molecules in the unit cell. The cell dimensions are: a = 10.41(2); b = 3.89(1); c = 19.14(4) Å; β = 96.1° (3). The structure was refined by the block‐diagonal least‐squares method to a final R value of 0.080 for 1111 observed reflections. The molecular dimensions are in good overall agreement with those in β form, while the packing is markedly different. Conjugation and planarity in the molecule are discussed.
Synthesis of 1H‐naphth[2,3‐d]imidazole‐4,9‐diones by acid catalyzed cyclization of 2‐Acylamino‐3‐amino‐1,4‐naphthoquinones
Authors: Carroll F. I. , Blackwell J. T. 
Published: March 2009

AbstractThe conversion of 2‐acylamino‐3‐amino‐1,4‐naphthoquinones (II) to the corresponding 2‐substituted 1H‐naphth[2,3‐d]imidazole‐4,9‐diones (I) under both alkaline and acid catalyzed conditions has been effected and the results compared. Treatment of 3‐(4′‐chlorobutanonyl‐amino)‐3‐amino‐1,4‐naphthoquinone (He) with aqueous ethanolic sodium hydroxide solution gives 1,2‐butanonaphth[2,3‐d]imidazole‐4,9‐dione (V); whereas, treatment of lie with refluxing formic acid gave 2‐(4′‐chlorobutyl)‐1H‐naphth[2,3‐d]imidazole‐4,9‐dione. Treatment of 2‐substi‐tuted 1H‐naphth[2,3‐d]imidazole‐4,5‐diones in DMF with alkyl halides in the presence of potassium carbonate affords the expected 1,2‐disubstituted naphth[2,3‐d]imidazole‐4,9‐diones (VI). The spectral properties of I, II, V and VI as well as those of some 2‐acylamino‐3‐chloro‐1,4‐naphthoquinones IV are discussed.
Insertion of chloral into linear and cyclic acetals
Authors: Dietrich H. J. , Karabinos J. V. , Raes M. C. 
Published: March 2009

AbstractContrary to the known difficulties of synthesizing dialkyl‐acetals of chloral, it was found that the latter can be quantitatively inserted into the COC bonds of cyclic, linear, substituted, or unsubstituted acetals at low temperatures in substantially anhydrous, acidic media, providing a variety of novel co‐acetals, including a 1,3,5,8‐tetraoxecane. The reaction was not applicable to ketals, where an aldol condensation was observed, nor to aldehydes other than chloral. A mechanism which avoids unstable chloral carbonium ion intermediates is discussed. In cases of substituted cyclic acetals or when two chloral units were added, often pure structural isomers were isolated, selectively formed by different Lewis acid catalysts.
Studies on the syntheses of heterocyclic compounds. Part CCCXXIX. Syntheses of i‐spiroisoquinoline derivatives by phenolic cyclization
Authors: Kametani T. , Kigasawa K. , Hiiragi M. , Ishimaru H. 
Published: March 2009

AbstractPhenolic cyclization of 2‐(3‐hydroxyphenyl)‐2‐methylethylamine (XIIIa) and 2‐(3‐hydroxyphenyl)phenethylamine (XIIIb) with various carbonyl compounds afforded eight types of corresponding 1‐spirocycloalkano‐ and 1‐spiroheterocycloalkano‐1,2,3,4‐tetrahydroisoquinoline derivatives (1‐VIII) and 1,1‐disubstituted‐1, 2,3,4‐tetrahydroisoquinoline derivative (IX). The acetyl derivatives of VI and IX and the benzoyl derivatives of III and V were also prepared. In addition, a synthetic method for obtaining the starting phenethylamines was examined.
Synthesis of 10‐deazariboflavin and related 2,4‐Dioxopyrimido[4,5‐b]quinolines
Authors: O'Brien Darrcll E. , Weinslock Louis T. , Cheng C. C. 
Published: March 2009

AbstractCondensation of substituted anthranilaldehydes with barbituric acid results in the formation of 2,4‐dioxopyrimido[4,5‐b]quinolines. Using this general synthetic approach, 7,8‐dimethyl‐2,4‐dioxo‐10‐ribityl‐2,3,4,10‐tetrahydropyrimido[4,5‐b]quinoline (10‐deazariboflavin) was prepared by the condensation of barbituric acid with 4,5‐dimethyl‐N‐ribitylanthranilaldehyde. The latter was obtainedin situby the treatment of 1‐[4,5‐dimethyl‐N‐(ribityl)anthraniloyl]‐2‐(p‐toluenesulfonyl)hydrazine, prepared from 4,5‐dimethylanthranilic acid with anhydrous sodium carbonate.
1,4‐Cycloaddition reactions. II. Preparation of p‐dioxino[2,3‐g]furo[3,2‐c] quinolines, p‐dioxino[2,3‐f] furo[3,2‐c] quinolines, and [1,3] dioxolo[4,5‐g] furo[3,2‐c] quinolines from 2,3‐dihydro‐5‐methylfuran and schiff bases
Authors: Perricone S. C. , Elslager Edward F. , Worth Donald F. 
Published: March 2009

AbstractThe boron trifluoride catalyzed 1,4‐addition of 2,3‐dihydro‐5‐methylfuran to N‐(p‐methoxy‐benzylidene)‐1,4‐benzodioxan‐6‐amine (II) gave 2 pairs of epimers, 2,3,3a,4,5,8,9,11b‐octahydro‐4‐(p‐methoxyphenyl)‐11b‐methyl‐p‐dioxino[2,3‐g]furo[3,2‐c]quinoline (IIIa and b) and 2,3,7,8,8a,9.10,1la‐octahydro‐8‐(p‐methoxyphenyl)‐11a‐methyl‐p‐dioxino[2,3‐f]furo[3,2‐c]quinoline (IVa and b). When N‐(p‐methoxybenzylidene)‐3,4‐methylenedioxyaniline (V) was condensed with 2,3‐dihydro‐5‐methylfuran in an analogous manner, a mixture of 2 epimers of 2,3,3a,4,5,10b‐hexahydro‐4‐(p‐methoxyphenyl)‐10b‐methyl[1,3]dioxolo[4,5‐g]furo[3,2‐c]quinoline (VIa and b) was isolated. Treatment of this mixture with sulfur afforded 6‐(p‐methoxyphenyl)‐8‐methyl‐1,3‐dioxolo[4,5‐g]quinoline‐7‐ethanol (VIII). Structural assignments for all of the products were made from NMR spectra. None of the compounds possessed appreciable biological activity.
Polarographic reduction of azines in acetonitrile
Authors: Millefiori Salvatore 
Published: March 2009

AbstractThe polarographic reduction potentials of some mono and diaza compounds were measured in acetonitrile solution and the reduction mechanism investigated by oscillopolarography and the Kouleckys analysis of the waves. Distinct regression lines were obtained for the two classes of compounds between the cathodic half‐wave potentials and the energy of the lowest unoccupied Hüekel π‐molecular orbital.
Synthesis of isoacronycine and its pyranone analog
Authors: Oh Chan Soo , Greco Claude V. 
Published: March 2009

AbstractThe Pechmann condensation of malic acid with 1,3‐dihydroxy‐10‐methyl‐9‐acridanone (6), performed during the search for a synthetic approach to 5‐methoxy‐2,2,11‐trimethyl‐2H‐pyrano[2,3‐b]acridan‐6‐one (isoacronycine, 11a), afforded 5‐hydroxy‐11‐methyl‐2H‐pyrano[2,3‐b)acridan‐2,6‐dione (7). This is the first example of a new heterocyclic ring system in which an acridanone and a pyranone ring have been fused. Compound 7 served as the intermediate for the preparation of 11a and was readily converted into the pyranone analog 9 of isoacronycine by known procedures. Spectral and chemical evidence distinguishing 11a from acronycine (12a) is presented.
Porphyrinogens and porphodimethenes, intermediates in the synthesis of meso‐tetraphenylporphins from pyrroles and benzaldehyde
Authors: Dolphin D. 
Published: March 2009

AbstractThe reaction between pyrroles and benzaldehyde in refluxing acetic acid gives meso‐tetraphenylporphins and chlorins. The initial condensations give a porphyrinogen which undergoes an acid catalyzed autoxidation to porphyrin via a porphodimethene. The chlorin is shown to be derived from the reduction of porphyrin.
Synthesis of 5‐lodo‐ and 5‐nitro‐3‐indolyl phosphates as cytochemical substrates for acid phosphatase
Authors: Rabiger Dorothy J. , Chang Mildred Y. , Matsukawa S. , Tsou K. C. 
Published: March 2009

AbstractThe synthesis of 5‐iodo‐3‐indolyl and 5‐nitro‐3‐indolyl phosphate for cytochemical demonstration of acid phosphatase is reported. Enzymatic hydrolysis of these compounds liberates the corresponding indoxyl which is oxidized to the substituted indigo at an acid pH. In contrast, the 5‐bromo and the unsubstituted indoxyl are not oxidized readily at an acid pH. Comparison of the UV and visible, spectra of the disubstituted indigo has offered a partial explanation for this difference. E.S.R. measurements showed that 5,5′‐diiodoindigo, unlike 5,5′‐dibromoindigo, gives a detectable radical ion at an acid pH.
Reactions of vinyl azides and β‐haloalkyl azides with active methylene compounds. Synthesis of 1‐vinyl‐1,2,3‐triazoles
Authors: L'abbé G. , Hassner Alfred 
Published: March 2009

AbstractA general synthetic approach to the yet unknown class of 1‐vinyl‐1,2,3‐triazoles is the condensation of active methylene compounds with vinyl azides or their precursors, the β‐haloalkyl azides, in the presence of an alkoxide. Triazole‐4‐carboxylic acids prepared in this manner are decarboxylated smoothly on heating above their melting point. The use of NMR spectra in the structure assignment of some of the triazoles is discussed.