bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ring closures from eneearbamoyl azides. Syntheses of tetrahydro‐3‐indazolinones and 4‐imidazolin‐2‐ones
Authors: Chupp John P. 
Published: March 2009

AbstractReaction of phosgene with cyclohexylidene amines gives good yields of (1‐eyclohexen‐l‐yl)‐carbamoyl chlorides (1). Compound 1 can be converted to the corresponding eneearbamoyl azide (2), which on pyrolysis gives an improved synthesis of 1‐substituted‐4,5,6,7‐tetrahydro‐3‐indazolinones (7). When 1 is substituted by an allylic rather than alkyl or aryl group, the major products are 4‐imidazolin‐2‐ones (8) accompanied by only minor amounts of 7. The thermolysis reaction has been extended to N‐allylcarbamoyl azides in general, thus providing a new and facile synthesis for 1,4‐disubstituted 4‐imidazolin‐2‐ones (9). A tentative mechanism is advanced, involving intermediate azide addition to the allylic double bond.
Isothiazoles II: 5‐chloro‐4‐isothiazolin‐3‐ones
Authors: Miller G. A. , Weiler E. D. , Hausman M. 
Published: March 2009

AbstractQuantitative gas chromatographic analysis of the 3‐hydroxyisothiazole product distributions formed in the chlorine induced cyclization of 3,3′ ‐dithiodipropionamide and 3‐mercaptopropion‐arnide has led to reaction conditions which yield respectively 3‐hydroxyisothiazole, 5‐chloro‐3‐hydroxyisothiazole, or 4,5‐dichloro‐3‐hydroxyisothiazole as the predominant product. The 4‐chloro analog was found in only small quantity. Similar glc analysis of the cyclization of N,N′‐dimethyl‐3,3′‐dilhiodipropionamide showed 5‐ehloro‐2‐methyl‐4‐isothiazolin‐3‐one to he the major 4‐isothiazolin‐3‐one product under varied conditions. Also, a representative series of 5‐chloro‐2‐subtiuted‐4‐isohiazolin‐3‐oncs were prepared under extrapolated reaction conditions.
Isothiazoles IV: 4‐isothiazolin‐3‐one i‐oxide and 1,1‐dioxides
Authors: Lewis S. N. , Miller G. A. , Hausman M. , Szamborski E. C. 
Published: March 2009

AbstractRepresentative 4‐isothiazolin‐3‐one I‐oxides and I, I‐dioxides have been prepared by the reaction of m‐chloroperbenzoic acid with the respective 4‐isothiazolin‐3‐ones. Chromic acid, dinitrogen tetroxide, and nitric acid have also been successfully employed in the oxidation of several 3‐hydroxyisothiazoles to their respective I‐oxides.
Reactions of tetrahydro‐as‐triazine‐3(2H)‐thiories with α, β‐difunctional compounds
Authors: Trepanier Donald L. , Krieger Paul E. 
Published: March 2009

AbstractThe results of allowing tetrahydro‐as‐triazine‐3(2H)‐thiones to react with various α,β‐diiunctional compounds, such as, α‐bromoethyl p‐toluenesulfonate, chloroacetaldehyde, α‐bromophenylacet‐uldehyde, phenaeyl bromide, chloroacetonitrile, α‐bromophenylaeelonitrile, and α‐cyanobenzyl p‐toluenesulfonate are discussed. These condensations give either a 5H‐thiazolo[3,2‐b]‐as‐triazine or a 2H‐thiazolo[2,3‐c]‐as‐triazine.
An investigation of the minimal structural conditions lor the dirnroth‐type rearrangement in the polyazaindolizine series
Authors: Guerret Patrick , Jacquier Robert , Maury Georges 
Published: March 2009

AbstractIn the imidazo[1,2]diazine series, only the imidazo[1,2‐a]‐ and [1,2‐c] pyrimidine systems were found to undergo a Dimroth‐type rearrangement under basic aqueous conditions. The electronic and steric factors influencing the rearrangement rates of methyl substituted imidazo‐[1,2‐a] pyrimidines are discussed.
Purine N‐oxides: XXXVII. Derivatives from 6‐chloropurine 3‐oxide
Authors: Giner‐Sorolla Alfredo 
Published: March 2009

AbstractInteraction of 6‐chloropurine 3‐oxide with several amines led to 6‐substituted purine 3‐oxides. 6‐Chloropurine 3‐oxide and selenourea gave 6‐selenopurine 3‐oxide. 6‐Mereaptopurine 3‐oxide, prepared from the 6‐chloro derivative and ammonium dithioearbonate, was transformed with chlorine and hydrogen fluoride into 6‐purinesulfonyl fluoride 3‐oxide which upon ammonolysis afforded purine‐6‐sulfonamide 3‐oxide. Methanelhiol and 6‐ehloropurint: 3‐oxide yielded the known 6‐methylthiopurine 3‐oxide, which by treatment with chlorine was oxidized to 6‐methyl‐sulfonylpurine 3‐oxide. Reaction of the latter with hydroxylamine led to an improved synthesis of 6‐hydroxylaminopurine 3‐oxide, which by interaction with manganese dioxide was transformed into 6‐nitrosopurine 3‐oxide.
Studies of polyazapentalenes. I. The preparation of 6‐dehydroindazolo[1,2‐a]benzotriazole
Authors: Tsuge Otohiko , Samura Hideo 
Published: March 2009

AbstractThe photolysis of 1‐(o‐azidophenyl)‐1H‐indazole (IV) has been found to give a mix ture of 6‐dehydroindazolo[1,2‐a]benzolriazole (VI) and 2,2′‐di(1‐indazolyl)azobenzene (VII). On the other hand, 1‐(o‐nilrophenyl)‐1H‐indazole (1) was reduced with triethyl phosphite, affording VI and dibenzo[a,i] indazolo[1,2,′3‐cd] indazolo[3,2,1‐fg]‐3,3a,5a,6,8a,8b‐hexaaza‐as‐indacene (XIa).
The stereochemistry of 1,6,7,12b‐Tetrahydro‐2H,4H‐[1,2] oxazino[3′,4′:1,2]‐pyrido[3,4‐b]indole and of 1,2,3,6,7,12b‐Hexahydro‐3‐methyl‐4H‐pyrimido[3′,4′:1,2]pyrido[3,4‐6] indole
Authors: Crabb T. A. , Mitchell J. 
Published: March 2009

AbstractFrom an analysis of nmr spectral data, 1,6,7,12b‐tetrahydro‐2H,4H‐[1,3 ]oxazino[3′, 4′ :1,2]‐pyrido[ 3,4‐b ]indole is shown to exist in solution at room temperature almost entirely in the cis‐fused ring conformation with the nitrogen lone pair bisecting the C4 methylene group whereas under the same conditions 1,2,3,6,7,12b‐hexahydro‐3‐methyl‐4H‐pyrimido[3′,4′:1,2] pyrido‐[3,4‐b ]indole exists as an approximately 50:50 equilibrium mixture of the cis and trans‐fused ring conformations.
Halogenated ketenes. XXIII. 2‐Oxetanones
Authors: Brady William T. , Patel Arvind D. 
Published: March 2009

AbstractThe cycloaddition of dichloroketene with several simple ketones to produce 2‐oxetanones is described. The ketene is generated in situ by the zine dehalogenation method and the zinc/zinc chloride activates the carbonyl group of the ketone. The cycloaddition of methylchloro‐ and methylbromoketenes with some activated carbonyl compounds is also deseribed.
Reactions of 4,5‐diaminouracils
Authors: Youssefyeh R. D. , Kalmus A. 
Published: March 2009

AbstractReactions of 4,5‐diaminopyrimidines with various phthalic derivatives, depending on the conditions employed, led to pyrimidines with a 5‐N‐substituted phthalamic acid (III), 5‐N‐substituted phthalimide (II) and 4,5‐bis‐N‐substituted phthalimide (VI).
Spirans XVIII . gem‐Dialkyl and spirotetrahydrocarbazoles
Authors: Rice Leonard M. , Sheth Bhagvandas S. , Wheeler James W. 
Published: March 2009

AbstractThe reactions of 4,4‐dialkylcyclohexanones, spiro[4.5]decan‐8‐one and various spiro[5.5]‐undecanones with phenylhydrazines to produce corresponding 3,3‐dialkyltetrahydro and spiro (cycloalkyl 1,n′)‐1′,2′,3′,4′‐tetrahydrocarbazoles (n = 1, 2 or 3) by the Fischer indole synthesis were examined. Structural assignment of the one isomeric product derived from spiro[5.5]‐undecan‐2‐one was obtained on the basis of pmr spectra.
Benzo[b] thiophene derivatives XVII. Electrophilic substitution of 4‐hydroxybenzo[b] thiophene derivatives
Authors: Campaigne E. , Dinner A. , Haseman M. 
Published: March 2009

AbstractA variety of eleclrophilic substitution reactions have been carried out on 4‐methoxybenzo[b]‐thiophene (IIIa) and 4‐benzoyloxybenzo[b ] thiophene (IVa). Substitution occurs in the 7‐position of IIIa and, with the exception of bromination, in the 7‐position of IVa. Bromination of IVa occurs in the 3‐position. Bromination of 4‐hydroxybenzo[b] thiophene (IIa) occurs in the 5‐position. The nmr spectra of eleven disubstituted benzo[b] thiophenes have been tabulated.
Geometrical isomerism of ethyl N‐(2‐pyridinyl)aminomethylenecyanoacetates
Authors: Nishigaki Sadao , Ichiba Misuzu , Shinomura Kazuko , Yoneda Fumio 
Published: March 2009

AbstractThe pure cis‐ and trans‐isomers of ethyl N‐(2‐pyridinyl)aminomethylenecyanoacetates were obtained and their structure and their interconvertibility is diseussed. 4H‐Pyrido[1,2‐a]pyrimidin‐4‐one‐3‐carboxylic acids were synthesized by treatment of both cis‐ and trans‐isomers with hydrochloric acid.
Synthesis of 5,12‐diazadibenz[a,h]anthracene
Authors: Klemm L. H. , Johnson W. O. , Weisert Annekäte 
Published: March 2009

Abstract5, 12‐Diazadibenz[a,h]anthracene (20) was synthesized in 21% overall yield for seven steps. Salient features of the synthesis include the initial, one‐step conversion of trans, trans‐1,4‐bis‐(β‐nitrovinyl)benzene into 2,2″‐dinitro‐p‐terphenyl by Diels‐Alder condensation plus elimination, monocyclization of the derived 2,2″‐diformylamino‐p‐terphenyl to give 8‐(2‐amino‐1‐phenyl)‐phenanthridine (10) in the presence of fortified polyphosphoric acid, and accomplishment of a second cyclization step only after reduction of the heteroring in 10 (by means of diisobutyl‐aluminum hydride) plus formylation. The 6‐methyl and 6,13‐dimethyl derivatives of 20 were prepared similarly.
Heterocycles. LXXXII. Some investigations on 1,2,3‐benzotriazines
Authors: Stanovnik B. , Tišler M. 
Published: March 2009

AbstractVarious 4‐substituted 1,2,3‐benzotriazines (2, 6, 7) have been prepared and of particular interest was the 4‐azido derivative (11) as a potential azidotetrazolo tautomerism exhibiting compound. However, no such interconversion could be established and this compound exists exclusively in the azido form. 2,5‐bis‐(Arylamino)‐1,3,4‐thiadiazoles (9) have been found to result from the reaction between 4‐hydrazino‐1,2,3‐benzotriazine and aryl isothiocyanates. In addition, a ring opening reaction between 4‐hydrazino‐1,2,3‐benzotriazine gave 2‐(tetrazol‐5″‐yl)‐2′,4′‐dihy‐droxyazobenzene (10) and photochemical conversion of the 4‐azido derivative gave s‐tetrazino‐[2,3‐b:5,6‐b′]diindazole(12).
Application of a thermal rearrangement reaction to questions of structure of condensed dihydrodiazepinones: Synthesis and characterization of isomeric dihydropyrido[3,4‐b] [1,4]diazepinones from 3,4‐diaminopyridine and ethyl acetoacetate
Authors: Israel Mervyn , Jones Lynne C. 
Published: March 2009

AbstractReaction of ethyl acetoacetate with 3,4‐diaminopyridine can theoretically give rise to the iso‐meric dihydrodiazepinones 1 and 3. However, only one of these (compound 1) was formed on direct condensation of the reactants in boiling toluene. The preparation of 3 required the synthesis of the pyridylaminocrotonate 2, which cyclized under conditions of base catalysis. When subjected to dry fusion, both diazepine derivatives rearranged to give isomeric isopropenylpyridoimidazol‐ones. The structures of these rearranged products were used to characterize the diazepines from which they were derived, according to a technique previously described (20,21). Our results contradict a recent report (17) ascribing structure 3 to the product from 3,4‐diaminopyridine and ethyl acetoacetate in boiling xylene.
7‐Benz[c] acridinemethanols as tetracyclic analogs of the 2‐phenyl‐4‐quinolinemethanol antimalarials
Authors: Rosowsky Andre , Chaykovsky Michael , Yeager Sandra A. , St. Amand Richard A. , Lin May , Modest Edward J. 
Published: March 2009

AbstractA series of new 7‐benz[c]acridinemethanols and 5,6‐dihydro‐7‐benz[c]acridinemethanols was prepared as rigid, tetracyclic analogs of the antimalarial 2‐phenyl‐4‐quinolinemethanols. Condensation of 5,7‐dichloroisatin with 6‐chloro‐, 7‐chloro‐, and 6,7‐dichloro‐1‐tetralone furnished halogenated 5,6‐dihydro‐7‐benz[c]acridinecarboxylic acids, which were transformed into the corresponding acid chlorides, acyl malonates, α‐bromomethyl ketones, and epoxides. Fully aromatic members of the series obtained via dehydrogenation of the 5,6‐dihydro acids were likewise converted into epoxides via the acylmalonate route. Although all the epoxides studied proved to be exceptionally resistant to ring‐opening by di‐n‐butylamine, probably on account of steric effects, they could be cleaved readily with piperidine or morpholine. Nmr spectra of the resulting amino alcohols suggest that these compounds exist in a single preferred conformation stabilized by internal O‐H····N hydrogen bonding, and that free rotation about the side chain C‐C bond does not occur at room temperature.
Studies on the syntheses of azole derivatives. Part IX. Formation of 2,4‐disubstituted δ2 ‐1,3,4‐oxadiazolin‐5‐one and 4‐substituted 1,2,4‐triazolidin‐3,5‐dione derivatives by thermal reaetion of N‐aryl‐N‐benzylearbamoyl azides
Authors: Kametani T. , Shibuya S. , Shio M. 
Published: March 2009

AbstractThe structure of the novel produets, 2,4‐ltis‐(N‐benzy1‐4‐nitroanilino)‐Δ2‐1,3,4‐oxadiazolin‐5‐one (VII), 2‐benzy1‐1‐(N‐benzy1‐4‐chloroanilino)‐4‐(4‐chlorophenyl)‐1,2,4‐triazolidin‐3,5‐dione (XIVa), and 2‐benzy1‐1‐(N‐benzylanilino)‐4‐pheny1‐1,2,4‐triazolidin‐3,5‐dione (XIVb), obtained upon thermal reaction of N‐bcnzyl‐N‐(4‐nitrophenyl)carbamoyl azide (la), N‐benzyl‐N‐(4‐chloro‐phenyl)carbamoyl azide (Ib) and N‐benzyl‐N‐phcnylcarbamoyl azide (le), respectively, were determined.
Preparation and thermal degradation of α,ω‐alkylene bis[5‐(1,2,3,4‐thiatriazolyl)] sulfides
Authors: Pilgram Kurt , Görgen Franz 
Published: March 2009

AbstractSyntheses of some extremely shock sensitive α,ω‐alkylene bis[ 5‐(1,2,3,4‐thiatriazolyl)] sulfides via reaction of sodium 1,2,3,4‐thiatriazoline thionate (1) and α,ω‐dihaloalkanes are described. Dichloromaleic imide reacted analogously with 1 to give 3,4‐bis(5‐(1,2,3,4‐thiatriazolyl)thio)maleic imide. The compounds decompose thermally in solution with formation of α,ω‐alkylene bis(thio‐cyanates), nitrogen and sulfur. The infrared spectra are discussed.
Reaction of 2,6‐dibutylaminohepta‐2,5‐dien‐4‐one with malononitrile
Authors: Van Allan J. A. , Reynolds G. A. 
Published: March 2009

AbstractMalononitrile reacted with the title compound to give 6‐amino‐5‐cyano‐2‐(3,3‐dicyano‐2‐methylallylidene‐4‐methyl‐2H‐pyran (3). Treatment of 3 with hot 80% sulfuric acid yielded 4,7‐dimethyl‐56‐hydroxy‐2(1H)quinolone. With concentrated aqueous sodium hydroxide, 3 gave 5‐amino‐3,6‐dicyano‐4,7‐dimethyl‐2(1H)quinolone and 5‐amino‐6‐carbamoyl‐3‐cyano‐4,7‐dimethyl‐2(1H)quinolone. The reaction of 3 with hydrochloric in acetic acid gave a mixture of 6‐amino‐3,7‐dicyano‐2,8‐dimethyl‐4‐quinolizone and 3‐cyano‐4‐methyl‐6‐(3,3‐dicyano‐2‐methylallyl)‐2‐pyrone. Compound 3 also reacted with methylamine, butylamine and piperidine to give 8‐amino‐5‐cyano‐4‐methyl‐2‐pyridone, 6‐bulylamino‐5‐cyano‐4‐methyl‐2‐pyridone and 5‐eyano‐4‐methyl‐6‐piperidino‐2‐pyridone respectively.
Synthetic quinine, analogs. V. Quinolinemethanols related to desvinylquinine
Authors: Bender D. R. , Coffen D. L. 
Published: March 2009

AbstractAldol condensation of quinolinecarboxaldehydes with 3‐quinuelidinone followed by acid‐catalyzed hydration of the resulting α,β‐unsalurated ketones provides a short and versatile synthesis of desvinylquinine derivatives. A novel rearrangement of 2‐(9‐phenanthrylmethylene)‐3‐quinuclidinyl earbinols leading to dibenzoindole derivatives is described.
Synthesis of some N‐substituted 6,7‐dimethoxy‐1,2‐benzothiazin(4H)‐3‐one 1,1‐dioxides
Authors: Catsoulacos P. 
Published: March 2009

AbstractSubstituted 1,2‐benzothiazin‐3‐ones have been prepared by cyclization of 4,5‐dimethoxy‐2‐carboethoxymethybenzenesulfonamides. The latter were obtained by the action of ammonia and primary and secondary amines on 4,5‐dimethoxy‐2‐carboethoxymethylbenzenesulfonyl chloride which in turn was obtained from ethyl 3,4‐dimethoxyphenylacetate and chlorosulfonic acid.
Photochemical preparation and rearrangement of some symmetrical methoxypyridyl phenyl glycols (pinacols)
Authors: Brown Ellis V. , Shambhu M. B. 
Published: March 2009

AbstractSolutions of 6‐methoxy‐3‐pyridyl phenyl ketone and 3‐, 4‐, 5‐ and 6‐methoxy‐2‐pyridyl phenyl ketones in isopropyl alcohol were subjected to ultraviolet radiation. All the ketones except 3‐methoxy‐2‐pyridyl phenyl ketone were observed to undergo bimolecular reduction to give the corresponding pinacols in 30‐100 percent yields. In cold concentrated sulfuric acid the pinacols were found to rearrange with the exclusive migration of the phenyl group. The pinacols hearing the 3‐pyridyl groups rearranged at a much faster rate than the 2‐pyridyl isomers.
N‐p‐toluenesulfonyl‐2‐oxazolidones Via the cycloaddition reaction of p‐tolucnesulfonyl isocyanate and epoxides
Authors: Herweh J. K. , Kauffman W. J. 
Published: March 2009

AbstractThe reaction of styrene oxide and phenyl glycidyl ether with p‐toluenesulfonyl isocyanate, employing a hydrocarbon‐soluble adduct of tributylphosphine oxide and lithium bromide as catalyst, results in excellent yields of the N‐p‐toluenesulfonyl‐2‐oxazoIidones. The 5‐isomeric‐2‐oxazolidone is obtained from phenyl glycidyl ether, but in contrast to conventional isocyanates, the p‐toluenesulfonyl isocyanate, upon reaction with styrene oxide, produces the 4‐isomeric 2‐oxazolidone as the major product. The effect of the N‐sulfonyl group on the nmr spectra of 2‐oxazolidones is discussed.
Reaction of β‐aeylarylhydrazines with dimethylformamide in the presence of calcium hydride. A novel route to 3‐pyrazolin‐5‐ones
Authors: Kornet Milton J. , Ong Tjoan Ho , Thio Poo An 
Published: March 2009

AbstractReaction of β‐acylarylhydrazines with calcium hydride in refluxing dimethylformamide (DMF) was found to lead to the formation of 2‐aryl‐3‐pyrazolin‐5‐ones (V). Application of this novel synthetic method resulted in fair to good yields of a series of 2,4‐diaryl‐3‐pyra7,olin‐5‐ones. The infrared spectra (potassium bromide) of the products (V) showed that these compounds exist as the laetim tautomer (VI). An oxindole (IIc) was obtained when dimethylbenzamide was substituted for DMF under similar reaction conditions.
The crystal and molecular structure of 1,1,4,4‐tetraphenyl‐1,4‐diphosphoniacyclohexane dibromide
Authors: Brown J. N. , Trefonas L. M. 
Published: March 2009

AbstractThe crystal and molecular structure of 1,1,4,4‐tetraphenyl‐1,4‐diphosphoniacyclohexane dibromide has been determined by a single‐crystal, x‐ray diffraction study using diffractometer data. The compound crystallizes in the monoclinic space group P21/c with unit cell constants of a = 12.777(1), b = 26.180 (2), c = 16.283 (1) Å, and β = 91.18(1)°. The structure was solved by the heavy atom method with the 4176 independent and statistically significant structure factors refining to a value of R = 0.07. The diphosphonium ring is in the chair conformation with each phosphorus ion having an axial and equatorial phenyl ring attached. P‐C and C‐C bond lengths of 1.78 ± .03 Å and 1.53 ± .03 Å respectively agree well with the literature value for these distances.
The effect of 4‐substituents on the stability of pyridinium dicarbethoxymethylides
Authors: Douglass James K. , Tabor M. Wilson , Spradling Julius E. 
Published: March 2009

AbstractThe effect of 4‐substituents on the stability of pyridinium dicarbethoxymethylides, as determined by pKa measurements, is found to correlate well with their effect on the stability of similarly substituted pyridine 1‐oxides. Displacements in chemical shift in the ylides, particularly of the α‐protons, are also found to correlate well with substituent effects. Intramolecular charge‐transfer transitions in the electronic spectra, characteristic of pyridinium ylides, are reported.
A mass spectrometric study of substituted furfuryl compounds
Authors: Loughran E. D. , Wewerka E. M. , Hammons G. J. 
Published: March 2009

AbstractThe mass spectra of six furfuryl compounds — namely, furfuryl alcohol, 5‐furfuryl‐furfuryl alcohol, difurfuryl ether, difurylmethane, 2,5‐difurfurylfuran, and 4‐furfuryl‐2‐pentenoic acid‐γ‐lactone — have been studied. Their fragmentation mechanisms are discussed in detail with particular emphasis on the modes that lead to the formation of aromatic fragments. The majority of the fragment ions are formed by elimination of CO and C2H2 from even‐electron precursor ions and HCO from odd‐electron precursor ions. Molecules containing two furan rings linked by a methylene group give mass spectra that exhibit large abundances of aromatic fragment ions.
Photo‐ and thermal elimination of nitrogen from 4‐phenyl‐ and 4,5‐diphenyl‐1,2,3‐triazole
Authors: Selvarajan R. , Boyer J. H. 
Published: March 2009

AbstractPhenylacetonitrile (2) (32%) and small amounts of benzyl methyl ether (3), benzonitrile (5) and methyl benzoate (6) were produced by irradiation of either 4‐phenyl‐1,2,3‐triazole (1) or 4‐phenyl‐5‐deutero‐1,2,3‐triazole (7) in methanol at 254 nm. In methylene chloride, irradiation of 1 produced 2 (15%) and small amounts of 3,6‐diphenyl‐1,2,4,5‐tetrazine (8). Irradiation of 4,5‐diphenyl‐1,2,3‐triazole (9) in methanol gave 2,4,5‐triphenylimidazole (11) (4%) and trace amounts of diphenylacetonitrile (10), benzamide (12), and compounds 3, 5, and 6. Irradiation of 2,3‐diphenyl‐2H‐azirine (13) in methanol gave small amounts of 3, benzaldehyde (4), and compounds 5, 6, 12 as well as 2,3,5,6‐tetraphenylpyrazine (14) and in methylene chloride it gave 11 (16%) and small amounts of 4, 5, 14, and acetophenone (15).On heating 4‐phenyl‐1,2,3‐triazole (1) in n‐hexadecane, elimination of nitrogen at 290° left phenylacetonitrile (2) as the only identified product. Similar pyrolysis of 4,5‐diphenyl‐1,2,3‐triazole (9) produced 2,3,5,6‐tetraphenylpyrazine (14) along with an intractable material. An efficient thermal isomerization of 2,3‐diphenyl‐2H‐azirine (13) gave 2‐phenylindole (17).
Pyrimido[5,4‐b]quinolines. I. Synthesis of substituted tricyclic systems related to riboflavin
Authors: Levine Edward M. , Bardos Thomas J. 
Published: March 2009

AbstractTwo alternative synthetic routes were investigated for the synthesis of 2,4,10‐substituted‐7,8‐dimethylpyrimido[5,4‐b]quinolines: (1) cyclization of 5‐(3,4‐xylidino)‐2,4‐disubstituted‐pyrimidine‐6‐carboxylic acids, and (2) cyclization of N‐5‐(2,4‐disuhstituted‐pyrimidinyl)‐4,5‐dimethylanthranilic acids. Route (1) invariably led to isomeric mixtures of the corresponding 7,8‐ and 8,9‐dimethylpyrimido[5,4‐b]quinolines which were difficult to separate, while route (2) yielded only the desired 7,8‐dimelhyl derivatives. The required intermediates were synthesized by Ullman‐type condensation of the appropriate pyrimidine and benzene derivatives. Cyclization with polyphosphoric acid, or phosphorus oxychloride (under various conditions) led to a number of new pyrimido[5,4‐b]quinoline derivatives, with oxo, methoxy and/or chloro substituents in the 2,4 and 10 positions. A mild, but effective chlorination procedure was developed for the chlorination of the 10‐(oxo) position without the cleavage of methoxyl groups at positions 2 and 4.
Reactions of dilithiooximes, dilithiophenylhydrazones and trilithiohydrazones with nitriles. Acid‐cyclization to isoxazoles or pyrazoles
Authors: Beam Charles F. , Foote Robert S. , Hauser Charles R. 
Published: March 2009

AbstractCertain C(α)O‐dilithiooximes, C(α)N‐dilithiophenylhydrazones, and C(α)N,N‐trilithiohydrazones were treated with a variety of nitriles. The intermediates were not isolated, but cyclized with acid to give isoxazoles or pyrazoles.
The conversion of isotopically labeled glycine to 1‐methyl‐2‐amino‐2‐imidazolin‐4‐one (creatinine)
Authors: Rowley G. L. , Kenyon G. L. 
Published: March 2009

AbstractA procedure is presented which allows the conversion of glycine to creatinine (1‐methyl‐2‐amino‐2‐imidazolin‐4‐one). The scheme was devised to optimize the yield based on the amount of glycine used so that the relatively readily available isotopically labeled glycines could be efficiently converted to the correspondingly labeled creatinines. In this case 1‐(13C)‐glycine was converted to 4‐(13C)‐1‐methyl‐2‐amino‐2‐imidazolin‐4‐one.