bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heterocyclic tautomerisms. I. An investigation of the 2‐arylbenzothiazoline‐2‐(benzylideneamino)thiophenol tautomerism. Part 1
Authors: Goetz Frederick J. 
Published: March 2009

AbstractA definite tautomeric relationship has been found between 2‐arylbenzothiazolines (I) and 2‐(benzylideneamino)thiophenols (II). In a reaction characteristic of the closed ring structure (I), 2‐arylbenzothiazolines were oxidized in high yield with benzoyl peroxide to the corresponding 2‐arylbenzothiazoles (III). Reactions characteristic of the open ring structure (II) include the formation of the potassium salt of the open ring structure (IV) by reaction of 2‐arylbenzothiazolines with potassium t‐butoxide in toluene and oxidation of 2‐arylbenzothiazolines to bis‐[2‐(benzylideneamino)phenyl] disulfides (V) by hydrogen peroxide in methanol.
Studies on the syntheses of heterocyclic compounds. CLXXIV. An approach to the synthesis of oxyacanthine and berbamine
Authors: Kametani Tetsuji , Lida Hideo , Kano Shinzo , Tanaka Sadao , Fukumoto Keiichiro , Shibuya Shiroshi , Yagi Haruhiko 
Published: March 2009

AbstractSchotten‐Baumann reaction of the amine (X) with 4‐benzyloxy‐3,4′‐oxydiphenylacetyl chloride (XI) gave two amides, (XIIa) and (XIIb), which were cyclized to give the corresponding 3,4‐dihydroisoquinolines, respectively. Methylation of the above 3,4‐dihydro‐isoquinolines, followed by hydrolysis, afforded the compounds having the same composition as berbamine (Ia) and oxyacanthine (Ib), whose structures are under examination.
Synthesis of 6‐hydroxymethyl‐1,3‐dimethyllumazine by rearrangement of the corresponding 6‐methyllumazine 5‐oxide
Authors: Zondler Helmut , Forrest H. S. , Lagowski J. M. 
Published: March 2009

AbstractStarting with a chloronitrouracil, the synthesis of 1, 3, 6‐trimethyllumazine has been achieved. Oxidation to the 5‐oxide and subsequent rearrangement gave 6‐hydroxymethyl‐1, 3‐dimethyllumazine. Because of the method of synthesis, the product is uncontaminated with the 7‐isomer.
The reaction of trans‐2‐aminocyclohexanol with formaldehyde
Authors: Crabb T. A. , Williams R. O. 
Published: March 2009

AbstractFrom a study of the geminal coupling constants for ‐O‐CH2‐N‐ protons structure II has been assigned to the product of the reaction between trans‐2‐aminocyclohexanol and formaldehyde. The previously proposed structure I is shown to be incorrect.
Researches on the reactivity of mannich bases part VIII synthesis of N‐methyl(vinylaryl)quinolinium salts and their photosensitivity
Authors: Andreani Franco , Andrisano Renato , Tramontini Maurilio 
Published: March 2009

AbstractDescribed in this communication is a new synthesis of N‐methyl‐4‐(vinylaryl)quinolinium salts by cyclization of the aminoketones, Ar‐CH=CH‐CO‐CH2‐CH2‐N(CH3)‐C6H4‐X. The aminoketones were obtained by replacement of the alkyiamino group of the ketoarylidene Mannich bases with various N‐methylarylamines. The U.V. spectra of the compounds were obtained. The photosensitivity characteristics in solution are reported. These data show the possibility of dimerization and probable trans → cis isomerization on exposure to visible and ultraviolet light.
Reissert compound studies. XV. preparation and reaction of the reissert anion at room temperature
Authors: Popp Frank D. , Wefer John M. 
Published: March 2009

AbstractThe anions (I and II) have been conveniently generated from the parent Reissert compounds in dimethylformamide using sodium hydride. Rearrangements to ketones, alkyl‐ations, and participation of I and II in other nucleophilic displacements have been investigated.
Irreversible enzyme inhibitors. XCI. candidate active‐site directed irreversible inhibitors of thymidylate synthetase. II. 2‐amino‐6‐methyl‐5‐(p‐tolylsulfonamidopropyl)‐4‐pyrimidinols with N‐substituents on the sulfonamide moiety
Authors: Baker B. R. , Coward James K. 
Published: March 2009

AbstractThree derivatives of 2‐amino‐6‐methyl‐5‐(p‐tolylsulfonamidopropyl)‐4‐pyrimidinol (I) with N ‐ substituents on the sulfonamide group, namely bromoacetamidopropyl (XVI), m‐bromoacetamidobenzyl (XXIVa), and p‐bromoacetamidobenzyl (XXIVb), were synthesized as candidate active‐site‐directed irreversible inhibitors of thymidylate synthetase. The bromoacetamidopropyl derivative, (XVI), the p‐bromoacetamidobenzyl derivative (XXIVb), and iodoacetamide showed irreversible inhibition of thymidylate synthetase, but XXIVa did not. Since iodoacetamide did inactivate the enzyme, but XXIVa did not, it cannot be ascertained whether XXIVb and XVI inactivate the enzyme by a random bimolecular mechanism or by the active‐site‐directed mechanism without evaluation of additional candidate inhibitors.Two synthetic routes were employed. The key intermediates for the bromoacetamidobenzyl sulfonamides (XXIV) were the corresponding nitrobenzyl sulfonamides (XXI); the latter were best prepared by reductive alkylation of 2‐amino‐5‐aminopropyl‐6‐methyl‐4‐pyrimidinol (XXV) with a nitrobenzaldehyde followed by tosylation. The key intermediate for XVI was a toluenesulfonamide with a carbobenzoxyaminopropyl substituent on the nitrogen (XIV); the latter was synthesized via N‐carbobenzoxy‐N'‐tosyl‐1,3‐diaminopropane (XI).
Reaction of thioxanthylium perchlorate with diazomethane
Authors: Seidl Helmut , Biemann Klaus 
Published: March 2009

AbstractThe reaction of thioxanthylium perchlorate with diazomethane was investigated. Depending on the reaction conditions, seven compounds (II, III, V, VI, VIII, IX, and X) are formed which were identified on the basis of spectral data (mainly mass spectra) and chemical reactions. A synthesis was worked out (reaction of compound VII with boron trifluoride) in which dibenzo[b,f]thiepine (VIII) is formed as major product (55%).
Irreversible enzyme inhibitors. XCIV. inhibition of dihydrofolic reductase with derivatives of 2,6‐diaminopurines
Authors: Baker B. R. , Santi Daniel V. 
Published: March 2009

AbstractIn order to gain additional information on the hydrophobic bonding region of dihydrofolic reductase, some derivatives of 2, 6‐diaminopurine with aryl or aralkyl groups at the N6, C8 and N9‐positions were investigated as inhibitors. Since none of the six compounds gave an increment in binding over the parent 2, 6‐diaminopurine, hydrophobic bonding to dihydrofolic reductase could not be detected with this ring system. Furthermore, 2, 6‐diaminopurine bridged from its 8‐position with methylene groups to the amino group of p‐aminobenzoic acid also failed to show an increment in binding.The 8‐substituted 2, 6‐diaminopurines were synthesized by base‐catalyzed cyclodehydration of the appropriate 5‐acylamido‐2, 4, 6‐triaminopyrimidines; the latter compounds were readily prepared by selective acylation of tetraaminopyrimidine.
The mass spectra of 1,2,4‐triazine and some of its derivatives
Authors: Paudler William W. , Herbener R. E. 
Published: March 2009

AbstractThe mass spectra of some esters of 1,2,4‐triazine‐3‐carboxylic acid and of 1,2,4‐triazine itself are reported, and their fragmentation patterns are analyzed.The syntheses of the methyl and of the t‐butyl esters of 1,2,4‐triazine‐3‐carboxylate are described.
Pyrrolopyrimidine nucleosides II. the total synthesis of 7‐β‐D‐ribofuranosylpyrrolo[2,3‐d]pyrimidines related to toyocamycin
Authors: Tolman Richard L. , Robins Roland K. , Townsend Leroy B. 
Published: March 2009

AbstractThe first synthesis of a 7‐β‐D‐ribofuranosylpyrrolo[2,3‐d]pyrimidine by direct ribosidation of a preformed pyrrolo[2,3‐d]pyrimidine has now been accomplished via the fusion procedure. Subsequent functional group transformations furnished the 6‐methyl‐thio derivative of the nucleoside antibiotic toyocamycin. Preparation of the 1‐, 3‐ and 7‐methyl isomers of 4‐amino‐5‐cyano‐6‐methylthiopyrrolo[2,3‐d]pyrimidine was accomplished and has provided an unequivocal assignment for the actual site of ribosidation by a comparison of ultraviolet absorption spectra. Factors utilized for the assignment of anomeric configuration are discussed.
Synthesis of possible metabolites of menazon
Authors: Stevens M. A. , Walker G. H. 
Published: March 2009

AbstractA product of the peracetic acid oxidation of 2,4‐diamino‐6‐methylthiomethyl‐1,3,5‐triazine is identical with a major urinary metabolite of the aphicide, menazon, in the rat. This product has been shown to be the S‐oxide 2,4‐diamino‐6‐methylsulphinyl‐methyl‐1, 3, 5‐triazine and not the N‐oxide.
Synthesis and properties of trimethylsilyl derivatives of vitamin B6
Authors: Sennello Lawrence T. , Kummerow F. A. , Argoudelis C. J. 
Published: March 2009

AbstractIn our studies on the biosynthesis of vitamin B6 in yeast (2), we are confronted with the problem of a fairly rapid assay of the different forms (known and unknown) of this nutrient that are excreted into the culture medium. The existing assay procedures for vitamin B6 are subject to at least one of several restrictions. They are time consuming, incapable of distinguishing between the three forms of the vitamin (pyridoxol, pyridoxal, and pyridoxamine), or preclude the regeneration and reisolation of the material after analysis.
Synthesis of vitamin B6 derivatives. III. 3‐ (4‐formyl‐3‐hydroxy‐2‐methyl‐5‐pyridyl)propionic acid, an analog of pyridoxal phosphate
Authors: Iwata Chuzo , Metzler David E. 
Published: March 2009

AbstractThe preparation and properties of a new analog of pyridoxal phosphate, 3‐ (4‐formyl‐3‐hydroxy‐2‐methyl‐5‐pyridyl)propionic acid and of the corresponding 4‐aminomethyl compound are described. The n.m.r. spectrum of the new aldehyde is compared with those of 5‐deoxypyridoxal and pyridoxal phosphate. The broad aldehyde proton peak of 5‐deoxypyridoxal is sharpened by heating, suggesting an equilibrium between two geometrical isomers. Mass spectra of the new aldehyde and of 5‐deoxypyridoxal are analyzed. The electronic absorption spectrum is nearly the same as that of 5‐deoxypyridoxal. The new aldehyde undergoes rapid transamination with amino acids, and the corresponding aminomethyl compound can be reoxidized to the aldehyde by heating with glyoxylic acid in aqueous solution.
The mass spectra of phosphorus esters. I. Bicyclic phosphites
Authors: Hendricker David G. 
Published: March 2009

AbstractThe mass spectra of bicyclic phosphites of the type P(OCH2)3CR, where R = CH3, C2H5, and C3H7 and NO2, are reported, and their fragmentation patterns analyzed. Unlike trialkyl phosphites, these cyclic phosphites do not yield a large number of phosphorus‐containing fragment ions resulting from hydrogen rearrangement.
Novel halogenated imidazoles. Chloroimidazoles
Authors: Lutz Albert W. , Delorenzo Sylvio 
Published: March 2009

AbstractWith one exception chloroimidazoles containing an unalkylated ring nitrogen have been ignored. Procedures are described using hypochlorite solution that permit the synthesis of 4,5‐dichloroimidazole and 2,4,5‐trichloroimidazole. Various bromoimidazoles are also converted to chloroimidazoles in refluxing hydrochloric acid.
Sulfostyrils. IV. Reactions of 4‐keto‐3,4‐dihydrosulfostyril
Authors: Loev Bernard , Snader Kenneth M. 
Published: March 2009

AbstractThe ketone group in 4‐keto‐3,4‐dihydrosulfostyril (I) displays anomalous properties. Its reactions are described; in some reactions it behaved normally, in others it proved quite inert. Attempted oximination of I led to extrusion of the sulfone group with formation of isatin derivatives. Compound I was converted to a tetracyclic indole derivative.
Syntheses of some analogs of a possible intermediate formed in the thymidylate synthetase reaction
Authors: Santi Daniel V. 
Published: March 2009

AbstractThe syntheses of a number of analogs of a possible intermediate formed in the thymidylate synthetase reaction are described. These consist of a number of 5‐arylaminomethyluracils (X) and N‐methyl‐N‐[1,‐(2′‐deoxy‐β‐D‐ribofuranosyl)thyminyl]‐p‐aminobenzoyl glutamic acid (XXb).
The preparation of triazines and benzimidazoles from 1‐ and 3‐cyanoisoquinolines
Authors: Case Francis H. , Kennon Lloyd 
Published: March 2009

AbstractThe preparation from 1‐ and 3‐cyanoisoquinolines of certain benzimidazoles and symmetrical triazines containing the ferroin group is described; also that of certain unsymmetrical triazines from 3‐cyanoisoquinoline.
Ion radicals. XIII. Spectroscopic and cryoscopic characterization of ions and ion radicals from phenothiazine and N‐methylphenothiazine in sulfuric acid solutions
Authors: Shine H. J. , Thompson D. R. , Veneziani C. 
Published: March 2009

AbstractThe formation and interconversion of the N‐methylphenothiazine cation radical and the N‐methylphenothiazine dication from both N‐methylphenothiazine and N‐methylphenothiazine S‐oxide in sulfuric acid solutions have been demonstrated with e.s.r. and absorption spectroscopy. Cryoscopic measurements have shown that in slightly aqueous sulfuric acid N‐methylphenothiazine S‐oxide is converted to the N‐methylphenothiazine dication and, analogously, phenothiazine 5‐oxide is converted to the protonated phenazathionium ion (the phenothiazine dication).
The preparation, structure and reactions of some “malonyl‐α‐aminopyridines”
Authors: Ingalls Elizabeth A. , Popp Frank D. 
Published: March 2009

AbstractThe reaction of several substituted 2‐aminopyridines with diethyl malonate was studied. The “methylmalonyl‐α‐aminopyridines” were shown to exist in the same tautomeric form as “malonyl‐α‐aminopyridine”. Formylation of these compounds takes place in the 3‐position and has led to the formation of a new tricyclic compound.
Friedländer syntheses with o‐aminoaryl ketones. III. Acid‐catalyzed condensations of o‐aminobenzophenone with polyfunctional carbonyl compounds
Authors: Fehnel Edward A. 
Published: March 2009

AbstractThe acid‐catalyzed condensations of o‐aminobenzophenone with a variety of diketones, ketoesters, ketoacids, and representatives of several other classes of polyfunctional carbonyl compounds containing the ‐COCH2 ‐ moiety have been investigated. Under the conditions used, normal Friedländer‐type ring‐closure was found to occur in all cases, giving good yields of substituted quinolines which have been identified as the 4‐phenyl analogs of the products obtained in classical base‐catalyzed Friedländer condensations with o‐aminobenzaldehyde. The method appears to be quite general and should provide a convenient synthetic route to a previously inaccessible series of 4‐arylquinolines.
Linear free energy relations and the hammett equation for substituted pyridine 1‐oxides
Authors: Nelson John H. , Garvey Roy G. , Ragsdale Ronald O. 
Published: March 2009

AbstractIt is recommended that a self‐consistent set of sigma constants be used to obtain linear free energy relations with pyridine 1‐oxides rather than using adjusted benzoic acid sigma constants. These recommended constants are derived from the literature values of the acid dissociated constants of the protonated substituted pyridine 1‐oxides. A survey and discussion of linear free energy relations using these new constants (σPyNO) is given. Comparisons of correlations using adjusted benzoic acid sigma constants and (σPyNO) are presented.
Some hydroxylated derivatives of chlorpromazine
Authors: Grotta H. M. , Page T. F. , Riggle C. J. , Manian A. A. 
Published: March 2009

AbstractAs part of a program to determine the metabolic fate of chlorpromazine [2‐chloro‐10‐(3‐dimethylaminopropyl)phenothiazine] (I), the synthesis of several hydroxylated derivatives of I was undertaken. This paper reports the preparation and structural verification of the 1‐ and 6‐hydroxy and the desdimethyl 3‐hydroxy derivative, and summarizes unsuccessful attempts to prepare the 4‐hydroxy derivative of I.
A study of the acylation of 4‐hydroxy‐6‐methyl‐2‐pyrone and 4 hy(lroxy‐6‐phenyl‐2‐pyrone
Authors: Marcus E. , Stephen J. F. , Chan J. K. 
Published: March 2009

AbstractThe acylation of 4‐hydroxy‐6‐melhyl‐2‐pyrone (1) and 4‐hydroxy‐6‐phenyl‐2‐pyrone (XXII) with aliphatic acid anhydrides, or with aliphatic acid chlorides in trifluoroacetic acid, has been found to product; first the corresponding ester, which then rearranges, partially or wholly, depending on the conditions and on the nature of the acyl moiety, to form the corresponding 3‐acylpyrone. With aromatic acid chlorides in pyridine or in trichloroacetic acid only the corresponding ester was obtained. These esters, however, could be rearranged to the corresponding 3‐acylpyrones with aluminum chloride. Acetoaeetylation of 1 and 4‐hydroxycoumarin (XXIX) with diketene gave, in both cases, the C‐acetoacetylated product.
Nucleophilic substitutions in some derivatives of 4‐ and 5‐nitroimidazoles
Authors: Sunjić V. , Fajdiga T. , Japelj M. , Rems P. 
Published: March 2009

AbstractHydrogen, as well as the halogen atom, at the 4 or 5 position in some 5‐ and 4‐nitroimidazoles were displaced by various nucleophiles such as the amino, cyano, hydroxy, and alkoxy groups. The greater reactivity of the departing group in the 4 position, which was regularly observed, is ascribed to the double activating effect of the azo and nitro groups. Cyanide ion in alcoholic solution reacted peculiarly with both 4‐ and 5‐nitroimidazoles giving o‐cyanoazoxyimidazoles as the only products. In some of the nucleophilic displacements at the 4 position of 5‐nitroimidazoles the formation of intermediate S̀‐complexes was observed.
Polyazanaphthylene nucleosides II. Synthesis of β‐D‐ribofuranosyl derivatives of 4‐quinazolone
Authors: Stout Mason G. , Robins Roland K. 
Published: March 2009

AbstractThe preparation of N1 (2,3‐O‐isopropylidene‐β‐D‐ribofuranosyl)‐4‐quinazolone (6) and N3‐β‐D‐ribofuranosyI‐4‐quinazolone (3b) are reported. The N3 derivative was prepared by the direct condensation of 4‐trimethylsilyloxyquinazoline (2) and 2,3,5‐tri‐O‐benzoyl‐D‐ ribofuranosyl bromide. The N1 derivative was prepared from the previously reported N1 ‐β‐D‐ribofuranosyl‐2,4‐quinazolinedione via the cyclonucleoside 4.
A study of some pyridopyrazines and pyridopyrimidines
Authors: Peck Robert L. , Day Allan R. 
Published: March 2009

AbstractThe d‐ and l‐forms of 2H‐octahydropyrido[1,2‐a]pyrazine (I) have been prepared and their absolute configurations established. These configurations were confirmed by an optical rotary dispersion study. The infrared spectra of 2H‐octahydropyrido[1,2‐a]pyrazine (I), lH‐octahydropyrido[ 1,2‐a]pyrimidine (11) and 2H‐octahydropyrido[ 1,2‐c]pyrimidine (111) were compared with the infrared spectrum of quinolizidine. All of these spectra showed the Bohlmann bands characteristic of a trans ring structure. A few derivatives of these ring systems have been prepared.
The kinetics of hydrogen‐deuterium exchange of methylisothiazoles
Authors: White James A. , Anderson Richard C. 
Published: March 2009

AbstractThe rates of hydrogen‐deuterium exchange of 3‐methyl, 4‐methyl, 5‐methyI and 3,5‐dimethyl‐isothiazole were determined and compared with the rate of exchange of 2‐methylpyridine. The rates were measured in dimethylsulfoxide‐d6 ‐deuterium oxide (90:10), using sodium deuteroxide as catalyst. The relative rates for exchange of both ring protons and methyl protons were 5 > 3 > 4. For exchange of methyl hydrogens, the approximate ratio of rate constants is 100:1:< 10−4 for positions 5,3, and 4, respectively. Activation parameters are reported for 5‐methylisothiazole.
Synthesis of (R)‐5‐(2′‐pentyl)barbituric acid derivatives of high optical purity
Authors: Cook C. E. , Tallent C. Ray 
Published: March 2009

AbstractNatural (R)‐(+)‐pulegone (1) was converted to 3‐methylhexanoic acid (4) by a sequence which precluded racemization. Conversion of this to malonic esters8, 5, and 11 permitted the synthesis of pentobarbital (6) secobarbital (12), thiopental (9),thiamylal(10), and 5‐(2′‐pentyl)barbituric acid (7), all having the (R)‐configuration in the side chain.
A study of electrophilic substitution in the pyrrolo[2,3‐d]pyrimidine ring
Authors: Gerster John F. , Hinshaw Barbara C. , Robins Roland K. , Townsend Leroy B. 
Published: March 2009

AbstractSeveral 4,5‐disubstituted pyrrolo[2,3‐d ]pyrimidines were prepared for the first time via electrophilic substitution, e.g. halogenation, nitration and sulfonation. PMR data for certain pyrrolo[2,3‐d]pyrimidines are included which has furnished conclusive evidence that electrophilic substitution occurred at position 5. These pyrrolo[2,3‐d]pyrimidines, with electron ‐withdrawing substituents at position 5, are of considerable interest as bases for the preparation of nucleoside derivatives related to tubercidin, toyocamcin and sangivamycin.
Reactions of 2,2,4,4‐tetramethyl‐1,3‐cyclobutanedione with amines and other nucleophiles. II
Authors: Hansen Gary R. , Demarco Ronald A. 
Published: March 2009

AbstractThe reaction of 2,2,4,4‐tetramethyl‐1,3‐cyclobutanedione with various nucleophiles has been demonstrated to be dependent on the reaction conditions, steric factors and the nucleophilicity of the attacking species. In the reaction with primary amines the intermediate has been established as the N‐substituted imine which is hydrolyzed to the corresponding amide in the presence of water. The reaction of diamines with the dione has been shown to be a method of synthesizing 2‐substituted imidazolines and 1 H‐4,5‐dihydropyrimidines.
4‐phenyl‐4H‐pyrazolo[3,4‐c] furazans. The reactions of 3,4‐dacylfuroxans with phenylhydrazine and with aniline
Authors: Bertelson Robert C. , Glanz Kenneth D. , Mcquain David B. 
Published: March 2009

AbstractThree different 3,4‐diaeylfuroxans (1) are shown to give 3‐substituted‐l‐phenyl‐4,5‐dioximino‐2‐pyrazolines (2) upon reaction with phenylhydrazine. The compounds 2 were dehydrated to 6‐sul)stituted‐4‐phenyl‐4H‐pyrazolo[3,4‐c]furazans. (3) and thermally converted to 3‐substituted 5‐imino‐4‐oximino‐1‐phenyl‐2‐pyrazolines (6). The compounds 1 react with aniline to give 3‐anilino‐4‐acylfurazans (10).
Reactions of 1,2‐dialkyl‐3‐pyrazolidinones
Authors: Kornet Milton J. , le Tan Sip 
Published: March 2009

AbstractThe condensation of 1,2‐dialkyl‐3‐pyrazoIidinones (1) with a series of aldehydes, ketones and esters in the presence of sodium hydride is described. Alkylation of I with several alkyl bromides gave 4‐alkyl substitution products in modest yield and reaction of 1,2,4‐trimethyl‐3‐pyrazolidinone with n‐butyl bromide gave a 4,4‐dialkylation product. Compound 1 reacted with aryl Grignard reagents to form 3‐aryl‐3‐pyrazoIines whereas the corresponding products were not realized in the case of alkyl Grignards. The reduction of a single example of 1 as well as the reduction of two 3‐pyrazolines to pyrazolidines is also reported.
Cinnolines. X. The oxidative‐rearrangement of 1‐aminooxindoles to 3‐cinnolinols
Authors: Baumgarten Henry E. , Wittman William F. , Lehmann Gerhard J. 
Published: March 2009

AbstractAn improved route for the oxidative‐rearrangement of 1 ‐aminooxindoles, treatment with equimolar amounts of t‐butyl hypochlorite, produces nearly quantitative yields of 3‐cinnolinols of excellent purity. The syntheses of the previously inaccessible 4‐ and 6‐ehloro‐1‐armnooxin‐doles has shown that this method, first applied to 1‐aminooxindole, may be reasonably general. The mechanism of this reaction is discussed in terms of nitrene and nitrenoid intermediates.
A new synthesis of anthyridine derivatives
Authors: Carboni S. , Da Settimo A. , Segnini D. 
Published: March 2009

AbstractAn Ullmann reaction between 2‐bromonicotinic acid and 2,6‐diaminopyridine gave 6 ‐amino‐2,2 ‐dipyridylamino‐3‐carboxylic acid (V). The latter was converted into 7‐amino‐5H‐dipyrido‐[1,2‐a:2,3 ‐d]pyrimidin‐5‐one (VII) by heating with polyphosphoric acid and into 2‐amino‐5,10 H‐anthyridin‐5‐one (VIII) by heating with concentrated sulfuric acid. Structure proofs of VII and VIII are given and some derivatives of VIII are described.
The reactions of 2,2‐difluoro‐4‐methylnaphtho[l,2‐e]‐1,3,2‐dioxaborin and its [2,1‐e]isomer with N,N‐dimethylformamide
Authors: Reynolds G. A. , Van Allan J. A. 
Published: March 2009

AbstractThe title compounds react with dimethylformamide in acetic anhydride to give dimethylamino‐vinyl derivatives which, on treatment with base, yield benzochroman‐4‐ones. The [1,2‐e] isomer reacts with the Vilsmeier complex to give 3‐formylbenzo[f]chrom‐4‐one and 9‐hydroxy‐1‐phenalenone, and the [2,1‐e]isomer gives 3‐formylbenzo[h]chrom‐4‐one.