bluuebunny/crossref_metadata_2025 huggingface dataset:
1,4‐Cyeloaddition reactions. IV. preparation of Cyclopenta[g]furo[3,2‐c]quinolines, Cyclopenta‐ [f]furo[3,2‐c]quinolines, Benzo[H]furo[3,2‐c]quinolines, and Furo‐ [3,2‐c]indeno[1,7‐gh] quinolines from 2,3‐Dihydro‐5‐methylfuran and schiff bases
Authors: Worth Donald F. , Perricone S. C. , Elslager Edward F.
Published: March 2009

The boron trifluoride catalyzed 1,4‐addition of 2,3‐dihydro‐5‐methylfuran to N‐(p‐methoxybenzylidene)‐5‐indanamine (VI) gave 2 pairs of epimers, dl‐3,3a,4,5,7,8,9,10b‐octahydro‐4‐(p‐methoxyphenyl)‐10b‐methyl‐2H‐cyclopenta[g]furo[3,2‐c]quinoline (VIIa and b) and dl‐3,3a, 4,‐5,8,9,10,10c‐octahydro‐4‐(p‐methoxyphenyl)‐10c‐methyl‐2H‐cyclopenta[f]furo[3,2‐c]quinoline (VIIIa and b). When 4‐(benzylideneamino)‐1‐naphthol (IXa) was condensed with 2,3‐dihydro‐5‐methylfuran in an analogous manner, a mixture of two isomers of dl‐1,2,2a,3,4,5a‐hexahydro‐5a‐methyl‐2‐phenylbenzo[h]furo[3,2‐c]quinolin‐7‐ol [Xa and b (R  H)] was obtained. Likewise, 4‐[(p‐hydroxybenzylidene)amino]‐1‐naphthol (IXb) and 4‐(p‐methoxybenzylidene)amino]‐1‐naphthol (IXc) gave a mixture of two isomers of dl‐1,2,2a,3,4,5a‐hexahydro‐2‐(p‐hydroxyphenyl)‐5a‐methylbenzo[h]furo[3,2‐c]quinolin‐7‐ol [Xa and b (R  OH)] and dl‐1,2,2a,3,4,5a‐hexahydro‐2‐(p‐methoxyphenyl)‐5a‐methylbenzo [h]furo[3,2‐c]quinolin‐7‐ol [Xa and b (R  OCH3)], respectively. The condensation of N‐(p‐methoxybenzylidene)‐5‐acenaphthenamine (XI) with 2,3‐dihydro‐5‐methylfuran afforded a mixture of two isomers of dl‐2,3,3a,4,5,9,10,‐11b‐octahydro‐4‐(p‐methoxyphenyl)‐11b‐methylfuro[3,2‐c]indeno[1,7‐gh]quinoline (XIIa and b). Structural assignments for all of the products were made from NMR spectra. None of these compounds possessed appreciable biological activity.
Studies in organic mass spectrometry. III. Adenosine 8‐Cyclonucleosides
Authors: Ikeda Masazumi , Tamura Yasumitsu , Ikehara Morio
Published: March 2009

The mass spectra of purine 8‐cyclonucleosides have been determined and compared with those of purine nucleosides. The mass spectra of the former are characterized not only by the presence of an intense molecular ion but also by the presence of the peaks corresponding to 8‐oxy (or 8‐thio) adenine and its protonated form due to a double and triple hydrogen transfer.
The syntheses of pyridazino[1,2‐a] pyridazine derivatives of furan, pyridazine and pyrrole by diels‐alder reactions
Authors: Gillis Bernard T. , Valentour James C.
Published: March 2009

Diels‐Alder adducts were formed in the lead tetraacetate oxidations of substituted cyclic hydrazides of furan, pyridazine and pyrrole dicarboxylic acids in the presence of 1,3‐cyclo‐hexadiene or 1,3‐cyclopentadiene. The products resulting were furo[3,4‐g]pyridazino[1,2‐a]‐pyridazine‐6,10‐diones, pyridazino[4,5‐g]pyridazino[1,2‐a]pyridazine‐6,11‐diones, and pyrrolo‐[3,4‐g]pyridazino[1,2‐a]pyridazine‐6,10‐diones, respectively. Some hydrogenations and ring opening reactions were studied.
2‐Carboazetidine derivatives
Authors: Rodebaugh Richard M. , Cromwell Norman H.
Published: March 2009

A reaction sequence is reported for converting methyl 7‐bromocrotonate to 1‐alkyl‐2‐carbo‐methoxyazetidines thus confirming our earlier structural assignments of these compounds obtained by a more direct route. Methods are described for obtaining azetidinyl alcohols, acids, amides, amines and ketones. 1‐t‐Butyl‐2‐carbomethoxyazetidine was observed to undergo ring opening to an acyclic γ‐aminohydrazide derivative when treated with hydrazine hydrate. On the other hand, the corresponding N‐benzylazetidine under similar conditions rearranged to 1‐benzyl‐2‐pyrrolidinone.
Reaction of 4,5‐diaminopyrimidines with 2,5‐hexanedione
Authors: Youssefyeh R. D. , Kalmus A.
Published: March 2009

Reaction of 2,5‐hexanedione with various 4,5‐diaminopyrimidines was found to lead to the formation of 5‐(N‐pyrryl)‐4‐aminopyrimidines. Structural assignments for the products obtained were made on the basis of nmr, ir, uv and mass spectral data.
Perchloroimidazo[1,2‐a] pyridine. Synthesis and nucleophilic substitutions
Authors: Paudler William W. , Pokorny David J. , Good James J.
Published: March 2009

Perehloroimidazo[1,2‐a]pyridine has been prepared and it has been shown that nucleophilic substitution occurs preferentially at C5 possibly followed by substition at C7.
Syntheses of some indazoles structurally related to equilenin
Authors: Morgan John G. , Berlin K. Darrell , Durham Norman N. , Chesnut Robert W.
Published: March 2009

This study reports the complete synthesis and characterization of the 15, 16‐diazaequilenin derivative 10,11‐dihydro‐3H‐naphth[1,2‐g]indazol‐7‐ol (2b) as well as the methyl ether 2a of the above compound and the novel “model” compound 4,5‐dihydro‐1H‐benz[g]indazol‐7‐ol (3b). Indazoles 2a and 3a have demonstrated in vitro activity against a variety of microorganisms.
Cyclization of ylidenemalononitriles. VII. Studies on sulfur‐containing heterocyclic systems
Authors: Campaigne E. , Burton H. R. , Blanton C. D. , Schneller S. W.
Published: March 2009

Ring closure of ylidenemalononitrile adducts has been extended to the syntheses of isomeric sulfur heterocycles. The malononitrile derivatives of thiochromanone, thiochromone and iso‐thiochromanone have been synthesized, and results of the acidic ring closure experiments on these compounds are reported. The thiochromanone adducts gave an interesting disproportionation reaction, and experiments designed to support the proposed route are presented.
Synthesis of 10‐deazapteroic and 11‐deazahomopteroic acids
Authors: Degraw Joseph I. , Tsakotellis Panayotis , Kisliuk Roy L. , Gaumont Yvette
Published: March 2009

The syntheses of 10‐deazapteroic and 11‐deazahomopteroic acids are described. These compounds along with their simple 6‐phenylalkylpteridinol relatives were found to be inactive as antimalarial agents against the Plasmodium berghei or Plasmodium gallinaceum strains. 10‐Deazapteroie acid was a potent growth inhibitor of Streptococcus faecium both in the pteridine and tetrahydropteridine forms.
Novel boron heterocycles. II. 2,3‐dihydro‐1,3,5,2‐oxadiazaboroles, 1,2‐dihydro‐1,3,2‐benzodiazaborine 3‐oxide, and 3,4‐dihydro‐2H‐1,2,4,3‐benzothiadiazaborine 1,1‐dioxide
Authors: Yale Harry L.
Published: March 2009

A number of arylamidoximes, an o‐aminobenzaloxime, and an o‐aminobenzenesulfonamide have been reacted with boronic acids to give three novel boron containing heterocycles. Evidence, based on mass spectroscopy, that the product from o‐aminobenzaloxime is a 1,2‐dihydro‐l,3,2‐benzodiazaborine 3‐oxide, is presented.
Synthesis of 3‐ and 4‐(β‐D‐ribofuranosyl)‐s‐triazolo[2,3‐a] pyrimid‐7‐one, isomers of inosine containing a bridgehead nitrogen atom
Authors: Winkley Michael W. , Judd Gerard F. , Robins Roland K.
Published: March 2009

The first synthesis of a purine nucleoside analog containing a bridgehead nitrogen atom is here reported. The direct glycosylation of the trimethylsilyl derivative of s‐triazolo[2,3‐a] pyrimid‐7‐one has been shown to give 3‐(β‐D‐ribofuranosyl)‐s‐triazolo[2,3‐a]pyrimid‐7‐one (V) and 4‐(β‐D‐ribof'uranosyl)‐s‐lriazolo[2,3‐α]pyrimid‐7‐one (VII). The nueleoside V may he considered a close analog of inosine in which the nitrogen N1 and C5 of inosine have been interchanged. Bro‐minalion of the tri‐O‐acelyl derivative IV gave, after deblocking, 6‐bromo‐3‐(β‐D‐ribofurnaosyl)‐s‐triazolo[2,3‐a] pyrimid‐7‐one (IX). Structural assignments of the nucleosides were made on the basis of comparison of the ultraviolet absorption spectral characteristics with 3‐methyl‐s‐triazolo‐[2,3‐a]pyrimid‐7‐one (XI) and 4‐methyl‐s‐lriazolo[2,3‐a Jpyrimid‐7‐one (XII) prepared by a standard procedure from 7‐methoxy‐s‐triazolo(2,3‐a] pyrimidine (X).
Organosilicon compounds XIII. Cleavage of the silicon‐carbon bond of 2‐trimethylsilylbenzothiazole
Authors: Pinkerton Frank H. , Thames Shelby F.
Published: March 2009

The high‐yield synthesis of 2‐trimcthylsilylbenzothiazole is described, and the labile nature of this silicon‐helerocyclic bond is proved when cleavage is affected by aldehydes, acid halides, chloro‐formates and anhydrides. Justification for this unusual reactivity and further insight into the reaction mechanism is offered.
Heterocyclic N‐glycosides. VIII. Anomerisation and rearrangement of 2′,3′‐unsaturated N‐glycosides
Authors: Fucrtes M. , Garcíaa‐Muñtoz G. , Madroñtro R. , Stud M.
Published: March 2009

The acid catalyzed transformation of cither 1‐(4 ‐O‐acety1‐2,3 ‐dideoxy‐α‐ or β‐L‐glycero‐pent‐2 ‐cnosyl)‐5,6‐dichlorobenzotriazole gave the same mixture of unsaturuted glycosides. The main three components of this mixture were the above α and β anomers and a glycal‐type compound which results from the allylic rearrangement of the 5,6‐dichlorobenzotriuzole moiety to the C‐3 position of the carbohydrate. Evidence is presented that these results can be rationalized as proceeding through an allylic carbonium ion. Preliminary experiments on transglycosidation reactions using 2′,3′‐unsaturated N‐glycosides are reported.
Nuclcophilic substitution reactions of 5‐acetoxymethyl‐and 5‐p‐nitrophenoxymethyluraeils
Authors: Santi Daniel V. , Pogololti A. L.
Published: March 2009

The synthesis of a number of 5‐acetoxymethyl‐ and 5‐p‐nitrophenoxymethyluracils and their nucleophilic substitution reactions with sodium methoxide and sodium borohydride are reported. These reactions all appear to involve intermediates with carbonium ion character, the formation of which are dependent upon structural features of the heterocycle. Most facile reactions occur when the 1‐position of the heterocycle can accommodate a negative charge to assist in the formation of highly reactive 5‐methenyluracil (VII) intermediates. Where ionization is precluded, as with 1‐methyl derivatives (IVb, VIb) displacements are retarded but may be assisted by addition of a nucleophilc to the 6‐position of the heterocycle. Analogous 1,3‐dialkylpyrimidines may react with nucleophiles at the 4‐carbonyl group to give anomalous products. Biological connotations of these reactions are discussed.
The stereochemical assignments of the four 8‐azaestrone configurational isomers
Authors: Brown Richard K. , Meyers A. I. , Trefonas L. M. , Towns R. L. R. , Brown J. N.
Published: March 2009

Complete correlation has now been accomplished for the four possible isomers in the 8‐azacstrone scries, synthesized by two different synthetic routes.
Studies on quinoline derivatives and related compounds. 1. A new synthesis of 1‐alkyl‐1,4‐dihydro‐4‐oxo‐3‐quinolinecarboxylic acids
Authors: Agui Hideo , Mitani Toru , Nakashita Mitsuo , Nakagome Takenari
Published: March 2009

A novel preparative method for 1‐alkyl‐1,4‐dihydro‐4‐oxo‐3‐quinolinecarboxylic acids was developed. The key process is the cyclization of N‐alkylanilinomethylenemalonales, which was effected successfully in the presence of polyphosphoric acid, polyphosphate ester, boron tri‐fluoride or a mixture of acetic anhydride and sulfuric acid. With phosphorus oxychloride, N‐alkylanilinomethylenemalonates yielded 1‐alkyl‐4‐chloro‐3‐carbethoxyquinolinium salts which were hydrolyzed readily to ethyl 1‐alkyl‐1,4‐dihydro‐4‐oxo‐3‐quinolineearboxylates or their acids. By means of this novel method several new 1‐alkyl‐1,4‐dihydro‐4‐oxo‐3‐quinolineearboxylic acids were prepared.
The synthesis and chemical reactivity of 6‐selenoguanosine and certain related derivatives
Authors: Milne George H. , Townsend Leroy B.
Published: March 2009

The synthesis of 6‐selenoguanosine (2) has been accomplished by a nucleophilic displacement of the chloro group from 2‐amino‐6‐chloro‐9‐(β‐D‐ribofuranosyl)purine (1) with either selenourea or sodium hydrogen selenide. Treatment of 2 with Raney nickel has revealed that the seleno group can be removed much easier under these conditions than the corresponding mercapto group. Alkylation of 2 with several alkylating agents occurred at the exocyclic 6‐seleno group to furnish several 6‐alkylseleno‐2‐amino‐9‐(β‐D‐ribofuranosyl)purines. Nucleophilic displacement of the 6‐benzylseleno group from 2‐amino‐6‐benzylseleno‐9‐(β‐D‐ribofuranosyl)purine (3c) with sodium methoxide has been observed to occur at a faster rate than that observed for the corresponding 6‐benzylmercapto derivative. A study on the relative stability between 2 and 6‐seleno‐9‐(β‐D‐ribofuranosyl)purine toward basic conditions has revealed that the amino group at position two imparts an increase in stability.
Condensed thiophenes from sulfur bridging. II. Catalyzed reaction of azabiaryls with hydrogen sulfide
Authors: Klemm L. H. , Mccoy D. R. , Klopfenstein C. E.
Published: March 2009

Sulfur bridging inlo the phenylpyridines, 2‐ and 3‐phenylquinolines, and the symmetric bi‐pyridines was effected by means of hydrogen sulfide and an alumina catalyst at 630° to give [1]benzothienopyridines, [1]benzothienoquinolines, and thienodipyridines, respectively. Structures of products were assigned on the bases of spectral and chromatographic studies, as well as of separate syntheses. Relative yields of the various products are rationalized in terms of a model for interaction between a chemisorbed sulfur atom and the substrate molecule.
Derivatives of 1‐azabicyelo[4.3.1]decane
Authors: Hammer Charles F. , Craig John H.
Published: March 2009

1‐Azabicyclo[4.3.1]decan‐3‐one has been synthesized via Dieckmann condensation and converted to the corresponding hydroxy and chloro derivatives.
Thieno[2,3‐d]pyrimidines. I. A new method for the preparation of esters and amides of thieno[2,3‐d] pyrimidine‐6‐carboxylic acids
Authors: Santilli Arthur A. , Kim Dong Han , Wanser Stephen V.
Published: March 2009

A novel method for the preparation of esters and amides of thieno[2,3‐d]pyrimidine‐6‐carb‐oxylic acids was described. A typical example was the direct formation of ethyl 5‐amino‐2‐methylthiothieno[2,3‐d]pyrimidine‐6‐earboxylate(IIIa) from 4‐chloro‐2‐methylthio‐5‐pyrimidine‐carbonitrile (Ia) and ethyl mercaptoacetate in refluxing ethanol containing sodium carbonate. Displacement of the methylthio group in IIIa by various amines gave the corresponding amino derivatives. The reactions of IIIa and related compounds with acetylating agents such as acetic anhydride or chloroacetyl chloride gave various products. Treatment of 5‐carbethoxy‐4‐chloro‐2‐phenylpyrimidine(IV) with methyl mercaptoacetate afforded the dechloro intermediate diester Va, which cyclized on reaction with sodium ethoxide to form methyl 5‐hydroxy‐2‐phenylthieno‐[2,3‐d]pyrimidine‐6‐carboxylate (Vla). The synthesis was expanded to include the preparation of various new 2,4,5‐trisubstituted thieno[2,3‐d]pyrimidine‐6‐carboxylic acid esters and amides (Charts I‐V).
Novel polycyclic heterocycles. VII. Synthesis of tetracyclic ketones and derivatives from tricyclic 5,11‐dihydrodibenz[b,e][1,4] oxazepines
Authors: Petigara Ramesh B. , Yale Harry L.
Published: March 2009

Michael addition of 5,11‐dihydrodibenz[b,e][1,4]oxazepines to acrylonitrile gave 5,11‐di‐hydrodibenz[b,e][1,4]oxazepine‐5‐propionitriles, which were converted to the corresponding methyl 5‐propionates. Mild alkaline hydrolysis of these esters furnished the key intermediates, the 5,11‐dihydrodibenz[b,e] [1,4]oxazepine‐5‐propionic acids. In the preferred procedure, these propionic acids were cyclized to the tetracyclic ketones in yields of 60‐90%, by the action of one equivalent of trifluoroacetic anhydride in benzene. When ring C was involved in cylcization, 1,2‐dihydro‐3H,7H‐quino[8,1‐cd][1,5]benzoxazepin‐3‐ones were obtained, and when ring A was involved, 1,2‐dihydro‐3H,8H‐quino[1,8‐ab] [4,1]benzoxazepin‐3‐ones were formed. With 1c, both modes of cyclization were observed. In an alternative procedure that gave lower yields, the propionic acids were first converted to the corresponding acid chlorides, and these were cyclized by means of anhydrous stannic chloride; as anticipated, the products by this method were identical with those obtained via the trifluoroacetic anhydride method. Several reactions of these tetra‐cylcic ketones, e.g., their ease of oxime formation, and dehydrogenation to the α,β‐unsaturated ketones, are described. The α,β‐unsaturated ketones do not form oximes.

The structures assigned to the ketones are based on interpretations of their pmr, uv, and ir spectra. These assignments were confirmed by an X‐ray analysis of a single crystal of one representative ketone, 2b; the X‐ray study was also useful in indicating the thermodynamically preferred conformation of 2b. The structures of all the other compounds followed from similar spectral interpretations. The mass spectra of a few compounds are also discussed.
Bicyclic bases Ambident anions as intramolecular nucleophiles in the formation of 2‐oxa‐5‐azabicyclo[2.2.1] heptane derivatives
Authors: Porloghese P. S. , Sepp D. T.
Published: March 2009

The intramolecular cyclization of the ambident anion 5 derived from condensation of N, O‐ditosylhydroxy‐L‐proline acid chloride with dimethyl malonate anion was studied under a variety of reaction conditions. Cyclization occurred solely by O‐alkylation to give 2‐oxa‐5‐azabicyclo[2.2.1 ]heptanes. The NMR speetra of the hicyclo compounds are diseussed.
Thiophene series. XV The effect of leaving groups on the reactivity of nitro‐activated thiophene derivatives with sodium thiophenoxide
Authors: Guanti Giuseppe , Dell'Erba Carlo , Macera Paola
Published: March 2009

The effect of leaving groups on the reactivity of 3‐X‐2‐nitrothiophene (1), 2‐X‐3‐nitrothiophene (II) and 2‐X‐5‐nitrothiophene (III) (X = Cl, Br, I, OC6H4NO2(p), SO2C6 H5) with sodium thiophenoxide has been examined.

The results show that the reactivity ratio kIII/kII is always greater than unity and is relatively uninfluenced by changing leaving groups compared to the ratio kI/kII. The ratio kI/kII is greater or smaller than unity, according to following patterns of leaving groups

Examination of the reactivity of the three series of compounds having Cl, Br, I and C6H4NO2(p) as leaving groups showed the absence of an “element effect” which indicates that in the transition states of these displacement reactions there is little breaking of the bond to the group being displaced.
Studies on the syntheses of azole derivatives. Part VIII. Photolysis of N‐aryl‐N‐benzylearbamoyl azides [studies on the syntheses of heterocyclic compounds. Part CDXV
Authors: Kametani Tetsuji , Shio Masahisa
Published: March 2009

Photolysis of N‐benzyl‐N‐phenylearbamoylazide (IVc) afforded 1‐benzy 1‐2‐benzimidazolinone (Ic), 2‐benzimidazolinone (IIe), 4‐benzy 1‐2‐benzimidazolinone (IIe), and 5‐benzy1‐2‐benzimidazo‐linone (IIf)‐ The same reaction of N‐benzyl‐N‐(4‐chlorophenyl) carbamoyl azide (IVd) gave 3‐benzyl‐1‐(phenylhydrazocarbonyl)‐2‐benzimidazolinone (VIb) besides the above four products. In the case of N‐benzyl‐4‐(4‐butoxyphenyl)carbamoyl azide (IVe), 1‐benzy1‐5‐butoxy‐2‐benz‐imidazolinone (1e), 5‐butoxy‐2‐benzimidazolinone (IId), 5‐benzy1‐2‐benzimidazolinone (IIf), and 4‐benzy1‐6‐butoxy‐2‐benzimidazolinone (IIg).
Isothiazoles I: 4‐isothiazolin‐3‐ones. A general synthesis from 3,3′‐dithiodipropionamides
Authors: Lewis Sheldon N. , Miller George A. , Hausman Martin , Szamborski Eugene C.
Published: March 2009

The syntheses of 3‐hydroxyisothiazole, 4‐methyl‐3‐hydroxyisothiazole, and a eomprehensive series of the respective 2‐substituted‐4‐isothiazoIin‐3‐ones have been achieved by the one‐step chlorination‐cyclization of the corresponding 3,3 ‐dithiodipropionamides. In several instances, 5‐chloro‐4‐isothiazolin‐3‐ones were isolated as side products; however, no 4‐chloro‐4‐isothiazo‐lin‐3‐ones were evident in the reaction mixtures. These observations, coupled with the exclusive 4‐ or 4,5‐halogenation of several preformed 4‐isothiazoIin‐3‐ones, support a proposed reaction pathway involving introduction of chlorine α to the sulfur atom in intermediate reaction products.
1,3,5‐Trisubstituted hexahy drotriazines as mannich reagents. I. Preparation of secondary aminomethyl sulfide hydrochlorides
Authors: Reynolds Delbert D. , Cossar Bernard C.
Published: March 2009

1,3,5‐Trisubstituted hexahy drotriazines react with hydrogen chloride in the presence of anhydrous solvents to form useful intermediates for the introduction of the RNHCH2‐ group into compounds which undergo the Mannich reaction. The effectiveness of the new aminomethyl‐ating agent has been demonstrated by the preparation of secondary aminomethyl sulfide hydro‐chlorides.
1,3,5‐Trisubstituted hexahydrotriazines as mannich reagents. III. Preparation and cleavage of 3,4‐dihydro‐6‐hydroxy‐3‐substituted‐2H‐1,3‐benzoxazine hydrochlorides
Authors: Reynolds Delbert D. , Cossar Bernard C.
Published: March 2009

3,4‐Dihydro‐6‐hydroxy‐3‐substituted‐2H‐1,3‐benzoxazine hydrochlorides have been prepared by the reaction of hydroquinones with novel aminomethylating reagents prepared from 1,3,5‐trisubstituted hexahydrotriazines. With these monooxazine hydrochlorides is formed an equal molar amount of an amine hydrochloride. Purification leads to low yields. This difficulty has been circumvented by the use of bis(alkoxymethyl)amines in the presence of anhydrous hydrogen chlorides. The monooxazines have been hydrolyzed to yield ortho‐secondary aminomethylhydro‐quinone derivatives.
Mass spectral fragmentation patterns of various 6‐substituted 2,4‐bis‐(m‐aminoanilino)‐s‐triazines
Authors: Karliner J. , Seltzer R.
Published: March 2009

The mass spectra of 6‐substituted‐2,4‐bis‐(m‐aminoanilino)‐s‐triazines were determined and found to be dominated by intense molecular ions (base peak), strong M‐H peaks and fragment ions diagnostic for the arylamino and C‐6 substituents. Mechanisms have been proposed for the formation of the major peaks in the spectra. Fragmentation pathways involving hydrogen transfer reactions have been rationalized by concomitant opening of the triazine ring rather than an amino‐imino tautornerization as previously suggested. Fragmentation reactions accompanied by rearrangement modes have also been encountered in some of the compounds studied.
Pyrrolopyrimidine nucleosides VII. A study on electrophilic and nucleophilic substitution at position six of certain pyrrolo[2,3‐d] pyrimidine nucleosides
Authors: Tolman Richard L. , Robins Roland K. , Townsend Leroy B.
Published: March 2009

A study involving the reactivity of the pyrrolo[2,3‐d] pyrimidine ring system at position 6 with another exocyclic group (CN or magnified image‐NH2) already residing at C5 has established that hydrogen and bromine are susceptible to electrophilic and acid‐catalyzed nucleophilic substitution, respect‐tively. In one instance a strong nucleophile (hydrazine) gave nucleophilic substitution at position 6 which was followed by a reaction with the o‐nitrile group to afford the tricyclic nucleoside 4,5‐diamino‐8‐(β‐D‐ribofuranosyl)pyrazolo[3′, 4′ :5,4] pyrrolo[2,3‐d] pyrimidine (4).
Synthesis and properties of some aryl‐s‐triazines
Authors: Gillespie J. S. , Acharya Satya Prakash , Davis R. E.
Published: March 2009

The synthesis and reactions of several substituted s‐triazines were studied in attempts to prepare 4,6‐bis(4‐chlorophenyl)‐s‐lriazine‐2‐carboxylie acid (2) and 2‐aldehyde (8). The 4,6‐bis‐(4‐chlorophenyl)‐s‐triazine derivatives were surprisingly inert to a variety of reagents. 4,6‐Bis‐(4‐chlorophenyl)‐2‐methyl‐s‐triazine (1) could not be oxidized with any of a variety of oxidants. On bromination 1 gave 4,6‐bis(4‐chlorophenyl)‐2‐dibromomethyl‐s‐triazine (4) which was resistant to hydrolysis but on oxidation with selenium dioxide gave 2. Compound 2 was also prepared by the oxidation of 4,6‐bis(4‐chlorophenyl)‐2‐hydroxymethyl‐s‐triazme (7) with potassium permanganate. Other reagents did not oxidize 7 to 8. 4,6‐Bis(4‐chloroanilino)‐2‐mcthyl‐s‐triazine (3) was also resistant to oxidizing agents. 2‐Diazomethy1‐4,6‐dichloro‐s‐triazine (11) on reaction with 4‐chloroaniline gave 4,6‐bis(4‐chloroanilino)‐2‐chloromethyl‐s‐triazine (12). All efforts to prepare 8 were unsuccessful.
Mcsoionic purinone analogs. I. Initial theoretical considerations
Authors: Coburn R. A.
Published: March 2009

Thirty mesoionic analogs of purin‐6‐one, ‐2‐one and ‐2,6‐dione have been formulated based upon reported simple monocyclie mesoionic systems and factors influencing their stability. lluckel molecular orbital calculations were performed for these structures employing the ω, ω′ ‐technique and the variation of resonance integrals with bond orders. The results provide predictions concerning the properties and stability of the analogs, assist the determination of reasonable synthetic goals, and serve as input for more sophisticated theoretical treatments.
Preparation of indoles from 4H‐3,1‐benzothiazines by extrusion of sulfur
Authors: Lednicer Daniel , Emmert D. Edward
Published: March 2009

Prolonged heating of a series of α ‐hydroxy‐α‐aryl‐o‐toluidines in the presence of base and carbon disulfide afforded the corresponding 4H‐3,]‐benzothiazine‐2‐thiones. Treatment of the thiolalkyl ethers of these compounds with strong bases led to ring contraction to the corresponding 2‐thioalkyl indole with concommitant extrusion of sulfur. The scope of the reaction was examined.
The synthesis of 1,3,4,5‐tetrahydro‐2,3‐benzoxazepines and 1,2,4,5‐tetrahydro‐3,2‐benzoxazepines
Authors: Pifferi G. , Consonni P. , Monguzzi R. , Omodei‐Salé A.
Published: March 2009

Condensation of o‐bromomethylphenethyl bromide with potassium salt of N‐hydroxyurethan afforded 3‐earbethoxy‐1,3,4,5‐tetrahydro‐2,3‐benzoxazepine, which was hydrolyzed to 1,3,4,5‐tetrahydro‐2,3‐benxoxazepine (III). The reaction of o‐aeetoxymethylphenethyl bromide (VIb) with potassium salt of N‐hydroxyurethan in DMF, gave a complex mixture, from which O‐[2‐(o‐acetoxymethylphenyl)(ethyl]‐N‐earbethoxyhydroxylamine (VIIa) was separated. Subsequent desacetylation to VIIb and halogenation yielded O‐[2‐(o‐bromomethylphenyl)ethyl]‐N‐carbethoxyhydroxylamine (VIIc). By treatment of VIIc with potassium hydroxide, 2‐carbethoxy‐1,2,4,5‐tetrahydro‐3,2‐benzoxazepine (X) was obtained together with small amounts of 6,15‐diearbethoxy‐5,6,8,9,14,15,17, 18‐octahy drodibe nzo[d,I]‐1,8‐dioxa‐2,9‐diazaeyclotetradec in e (XI). Hydrolysis of X with potassium hydroxide gave 1,2,4,5‐tetrahydro‐3,2‐benzoxazepine (XII).

N‐Alkyl and N‐acyl derivatives of III and XII were also prepared.
Reactions of 4‐pyrones with primary amines. A new class of ionic associates
Authors: Van Allan J. A. , Reynolds G. A. , Alessi J. T. , Chang S. Chie , Joines R. C.
Published: March 2009

Primary aliphatic amines react with 2,6‐dimethyl‐4‐pyrone to give 2,6‐dialkylamino‐2,5‐heptadien‐4‐one derivatives. When the alkyl group was methyl, the diamino derivative cyclized on warming to give 1,2,6‐trimethyl‐4‐pyridone. The corresponding butylamino derivative did not thermally cyclize, but did give a pyridone on treatment with acid. The isopropylaminoketone did not cyclize. Several examples of 1,2,6‐trisubstituted‐4‐pyridones formed “ionic associates” consisting of two parts of the pyridone and one part of perchloric acid. These associates are useful primary standards for nonaqueous titrations.
Chemistry of thienopyridines. XII. Selective formation of N‐oxides, sulfoxides, and sulfones in some tricyclic systems
Authors: Klemm L. H. , Mathur S. B. , Zell Reinhard , Merrill R. E.
Published: March 2009

Direct conversion of [1]benzothieno[3,2‐b]pyridine (IVa), thieno[3,2‐b:4,5‐b']dipyridine (Va), and thieno[2,3‐b:4,5‐b']dipyridine (VIa) into their sulfoxides was effected by means of an equimolar quantity of iodobenzene dichloride in aqueous acetonitrile. Treatment of IVa‐VIa with excess chlorine gas in carbon tetrachloride and then with water gave the corresponding sulfones, IVc‐VIc. Hydrogen peroxide in glacial acetic acid converted Va and VIa into di‐N‐oxides, thieno[3,2‐b]pyridine into its N‐oxide, and sulfone VIc into an N‐oxide sulfone (X). Spectral and chemical means of distinguishing amongst the oxide functions are noted, and rationalizations for selectivity in the oxidations are discussed.
Synthesis of some derivatives of 4‐phenoxathiinearboxylie acid
Authors: Wu M. T. , Gay W. A. , Lyle R. E.
Published: March 2009

The preparation of a series of amino acid derivatives of 4‐phenoxathiincarboxylic acid is described.
The reaction of trivalent phosphorus nucleophiles with phenyl azidoformate and 5‐aryloxy‐1,2,3,4‐thiatriazoles
Authors: Pilgram Kurt , Görgen Franz , Pollard Clenn
Published: March 2009

Benzoyl azide and phenyl azidoformate react with phosphorous triamides (8) to give isolable phosphazides (11 and 12) which decompose thermally to give the corresponding acylated iminophosphoranes (13 and 14). With 5‐aryloxy],2,3,4‐thiatriazoles (15) and 8, 1:1 reaction products are formed which are best represented by the 2,2‐dihydro‐1,3,4,5,2‐thiatriazaphosphorine (23) structure. This structure assignment is based on thermal degradation studies and on the interpretation of infrared data of the 1:1 adducts; their mass spectra show fragmentation patterns in accordance with their formulation.
Conformalional analysis of azetidines‐evidenee for a non‐planar ring
Authors: Higgins Robert H. , Cromwell Norman H. , Paudler William W.
Published: March 2009

The proton coupling constants and particularly chemical shifts of a series of 1‐alkylazetidines, 1‐alkylazeudin‐3‐ols, 1‐alkyl‐3‐methylazetidin‐3‐ols, and C‐methylazetidines are rationalized in terms of a conformationally mobile, non‐planar azetidine ring. Preferred conformations for these compounds are discussed.
Synthesis of some simple actinomycin analogs
Authors: Wu M. T. , Lyle R. E.
Published: March 2009

The synthesis of some simple actinomycin analogs, using 3‐nitrosalicylic acid as a starting material, is reported.
Bieyclic bases . Synthesis and stereochemical studies of chiral 5‐substituted N‐tosyl‐2‐azabicyclo[2.2.1[ heptanes
Authors: Portoghese P. S. , Lattin D. L. , Telang V. G.
Published: March 2009

The synthesis of chiral exo and endo 5‐sulbstituted N‐losyl‐2‐azabicyclo[2.2.1]heptanes is reported. The nearly identical exo‐endo equilibrium ratios of the title compounds and the carbocyclic analogs suggest that their geometries and sterie interactions are quite similar.
Cyclic phosphonium ylides
Authors: Davies Maureen , Hughes A. N.
Published: March 2009

Synthetic approaches to cyclic phosphonium ylides are reviewed and the syntheses are classified according to reaction type rather than ring size. Particular attention is paid to syntheses leading to isolable or easily characterizable cyclic ylides and a number of other reactions in which cyclic phosphonium ylides are postulated as transient intermediates are discussed. There is also a brief discussion regarding structure and bonding in certain of the more stable cyclic ylides such as the 1,1‐disubslituted phosphorins and certain diphosph(V)orins.
The reduction and hydrolysis of some 7,7‐diethylpyrazolo[1,2‐a]‐pyridazine‐6,8(7H)dione derivatives
Authors: Gillis Bernard T. , Izydore Robert A.
Published: March 2009

The chemistry of several of the Diels‐Alder adducts formed by the reaction of 4,4‐diethylpyrazoline‐3,5‐dione (1) with conjugated dienes was studied with respect to reduction (hydride and catalytic) and reaction with base. Reaction of the 2,3‐dimethyl‐1,3‐butadiene adduct with lithium aluminum hydride followed by hydrogenation gave 1,3,5,6,7,8‐hexahydro‐cis‐endo‐6,7‐dimethyl‐2,2‐diethylpyrazolo[1,2‐a]pyridazine (11). Attempted conversion of this compound to 3,3‐diethyl‐cis‐7,8‐dimethyl‐1,5‐diazacyclononane (12) gave instead a compound which has been tentatively identified as N‐(2,3‐dimethyl‐4‐aminobutyl)‐2‐ethyl‐2‐methylbutanaldimine (14). Lithium aluminum hydride reduction of 4,4‐diethylpyrazolidine‐3,5‐dione (22) or the adducts formed from 1 and cyclopentadiene or 1,3‐cyclohexadiene gave good yields of 4,4‐diethylpyrazolidine (21). This later reduction gave a new and efficient synthetic route to the pyrazolidine ring system. Lithium aluminum hydride reduction of 5,6,7,8‐tetrahydro‐5,8‐ethano‐2,2‐diethylpyrazolo[1,2‐a]pyridazine‐1,3(2H)dione (26) followed by hydrogenolysis led to a high yield of 4,4‐diethyl‐2,6‐diazabicyclo[5.2.2]undecane (28) which is the first reported example of this ring system. Reaction of several of the adducts with ethanolic potassium hydroxide resulted in the opening of the five‐membered ring.
Studies on the syntheses of heterocyclic compounds. part CDLV. The mass spectral investigation and synthesis of the ochotensinan skeleton
Authors: Kametani T. , Hibino S. , Shibuya S. , Takano S.
Published: March 2009

Syntheses of several 1‐spiroisoquinoline derivatives (VIII, IX, X, XI, XII, XIII, and XIV) were carried out and their unique mass spectral fragmentations were reported. The presence of carbonyl groups at the C‐9 and C‐14 positions caused cleavage of the five membered ring through the elimination of one or two carbon monoxide groups. This led to the formation of the three membered ring system on the fragmentation pathway.
The synthesis of 1,4‐diazacycl[3,2,2]azine
Authors: Paudler William W. , Vandahm Richard A. , Park Young N.
Published: March 2009

The diazaanalog of “cycl[3,2,2]azine”, “1,4‐diazacycl[3,2,2]azine” (1,4,7b‐triazacyclopent‐[cd]indene) and its 2‐methyl derivative were prepared. These compounds are subject to facile acid‐catalyzed hydrolysis affording substituted imidazo[1,2‐a]pyridines.
5‐Azapurines and the structures of sym‐triazole intermediates
Authors: Hirata Tadashi , Twanmoh Li‐Ming , Wood Harry B. , Goldin Abraham , Driscoll John S.
Published: March 2009

Several isomers are possible when an isocyanate or an isothiocyanate is allowed to react with 3‐amino‐1,2,4‐triazole. It was found that variations in reagents or reaction conditions could be used to produce isomeric derivatives. The effect of substituents on the chemical shifts of adjacent ring protons is described for a number of new triazole derivatives. These data can be used to assign structures to new sym‐triazole reaction products. Appropriate triazoles were used as intermediates in the synthesis of s‐triazolo[1,5‐a]‐s‐triazine (5‐azapurine) derivatives. Spectral properties, methods of synthesis, and modes of degradation are described for several new members of this ring system.
The crystal and molecular structure of 1,1,2,4,4,5‐hexaphenyl‐1,4‐diphosphoniacyclohexadiene‐2,5 dibromide
Authors: Brown J. N. , Trefonas L. M.
Published: March 2009

The crystal and molecular structure of 1,1,2,4,4,5‐hexaphenyl‐1,4‐diphosphoniacyclohexadiene‐2,5 dibromide has been determined by a single crystal, x‐ray diffraction study using diffractometer data. The compound crystallizes in the space group P21/c with unit cell constants a = 8.813(1), b = 36.736(4), c = 12.478(1) Å, and β = 120.91°(1). The structure was solved by the heavy atom method and refined by block‐diagonal least‐squares to a final R = 0.04 for the 2761 statistically significant reflections. The structure determination shows that the central phosphonium ring is a diene and not a delocalized structure as anticipated. The ring is in the boat conformation with the axial phenyl rings aligned essentially parallel to each other and 3.55 Å apart.
Model photostable compounds
Authors: Otterstedt Jan‐Erik Anders , Pater Richard
Published: March 2009

The photostabilities and syntheses of 2,2′‐bis(o‐hydroxyphenyl)‐5,5′‐bipyrimidine, 6,6′‐bis(o‐hydroxyphenyl)‐3,3′‐bipyridine and 3,8‐bis(o‐hydroxyphenyl)‐4,7‐phenanthroline are discussed. The syntheses of parent compounds lacking the o‐hydroxy groups are also described.
6H‐indeno[1,2‐b]pyrido[3,2‐e]pyrazines. A new heterocyclic ring system
Authors: Israel Mervyn , Jones Lynne C. , Modest Edward J.
Published: March 2009

Condensation of 1,2‐indanedione and 1,2,3‐indanetrione hydrate (ninhydrin) with 2,3‐diamino‐pyridines gave a number of compounds belonging to the hitherto unknown 6H‐indeno[1,2‐b]‐pyrido[3,2‐e]pyrazine ring system. The unsymmetrical nature of the reactants can theoretically result in isomeric ring closure products. Assignment of the 6H‐ ring system was based upon the identity of 6H‐indeno[1,2‐b]pyrido[3,2‐e]pyrazin‐6‐one obtained from 2,3‐diaminopyridine and ninhydrin with material prepared by unequivocal synthesis. The direction of cyclization of ninhydrin and 1,2‐indanedione with the diamines was shown to be the same by reduction of the indenopyridopyrazinones to the corresponding indenopyridopyrazines. Some physical, chemical, and tumor growth‐inhibitory properties of the products are reported.
Chemistry of thienopyridines. XIII. Selective formation of sulfones in Bi‐ and tricyclic Systems. Thieno[2,3‐b]pyridine 1,1‐dioxide as a dienophile
Authors: Klemm L. H. , Merrill R. E.
Published: March 2009

Bicyclic and tricyclic thienopyridines are converted into sulfones in 13‐73% yield by means of acid‐hypochlorite. The sulfone thieno[2,3‐b]pyridine 1,1‐oxide (Ib) undergoes Diels‐Alder condensation with furan (both exo and endo products formed), anthracene, and naphthacene. Self‐condensation of Ib occurs with elimination of sulfur dioxide to give 8‐(3‐pyridyl)quinoline (XV). The structure of XV was established by means of pmr and a europium shift reagent. Ultraviolet, pmr, and mass spectral data for various compounds are presented and discussed.
A synthetic entry into the 2‐ and 3‐substituted‐methyl 2,3‐dihydro‐1,4‐benzoxazine series
Authors: Potter G. W. H. , Monro A. M.
Published: March 2009

Nmr spectroscopy has been used to demonstrate that the reported preparation of supposed 3‐bromomethyl‐2,3‐dihydro‐1,4‐benzoxazine (3) is in error, the product of the reaction being in reality a monocyclic compound, 4. An alternative entry to the 3‐substituted series is described in the synthesis of the 3‐hydroxymethyl derivative, 10, the structure of which was established by nmr and mass spectroscopy. The previous assignment of structure to 2‐carbethoxy‐2,3‐dihydro‐1,4‐benzoxazine, prepared by an ambiguous route, and to compounds derived from this ester, is shown to be correct.
Synthesis of some binaphthoxazoles
Authors: Kaempfen H. X.
Published: March 2009

Four of the six possible 2,2′‐binaphthoxazoles, as well as several of their cyano derivatives, have been prepared. Naphth[2,3‐d]oxazole was synthesized for the first time and 2,2′‐binaphth‐[2,3‐d]oxazole was made using a previously reported technique in which an incorrect assumption was made.
N,N'‐bis(substituted phenyl)‐1,2,4,5‐benzenetetracarboxylic‐1,2:4,5‐diimides
Authors: Mosher William A. , Chlystek Stanley J.
Published: March 2009

The preparation of N,N'‐bis(substituted phenyl)‐1,2,4,5‐benzenetetracarboxylic‐1,2:4,5‐di‐imides by the reaction of 1,2,4,5‐benzenetetracarboxylic‐1,2:4,5‐dianhydride (1) with aryl‐amines and with aryl isocyanates is described. Correlations are made between the properties of these diimides and the nature and position of the substituents in the phenyl ring. The condensation of dianhydride 1 with diisocyanates yields polymers varying from soft elastomers to tough films, depending upon the amount of imide structure in the polymer chain.
Some observations on märkl's cyclic phosphonium salt synthesis. The synthesis of a phosphocane
Authors: Marsi Kenneth L. , Lynch Donald M. , Homer G. David
Published: March 2009

Märkl's cyclic phosphonium salt synthesis was studied and some mechanistic conclusions drawn. The reaction was found to be generally applicable to the synthesis of C‐methylated five‐, six‐, seven‐ and eight‐membered ring systems. The first authenticated synthesis of a phosphocane is reported.
The crystal and molecular structure of 2,5‐dichloro‐3‐methoxypyrazine
Authors: Carter D. R. , Boer F. P.
Published: March 2009

A three‐dimensional X‐ray structure determination of 2,5‐dichloro‐3‐methoxypyrazine has been completed with diffractometer data. The crystals are monoclinic, space group P21/c, with lattice constants a = 4.059, b = 15.773, c = 11.123Å and β = 90.96° (Z = 4). The structure was solved by Sayre's equation and all hydrogen atoms were located by difference synthesis. Full‐matrix least‐squares refinement of all position parameters, hydrogen isotropic temperature factors, and anisotropic temperature factors for all other atoms converged at R = 5.7% for the 1397 reflections above background. Bond distances and angles are consistent with literature values.
The crystal and molecular structure of 3,5‐Di‐(t‐butyl)‐1‐phenylphosphoryl‐4‐aza‐2,5‐cyclohexadiene
Authors: Hungerford Lynn , Trefonas L. M.
Published: March 2009

The crystal and molecular structure of the title compound (C18H26NOP) has been determined by a single crystal, x‐ray diffraction study using Cu‐Kα. radiation. The compound was found to crystallize in the orthorhombic space group Pnma with unit cell constants a = 12.686 ± .001 Å, b = 14.776 ± .001 Å, and c = 9.540 ± .001 Å. The structure was solved by the heavy atom method and refined by block‐diagonal least‐squares to a final R = 0.099 for the 696 statistically significant reflections. The compound exhibits orientational disorder in the crystalline state. Nevertheless, the planarity of this ring; the lengthening of the diene carbon‐carbon bond to 1.41 Å the resultant shortening of both the carbon‐nitrogen bond (1.43 Å) and the carbon‐phosphorus bond (1.74 Å), and the CNC bond angle of 121° all strongly support the assumption of delocalization of the diene π‐electrons within the heterocyclic ring system.
Hypocholesterolemic alkaloids of lentinus edodes (berk.) sing. II. A novel synthesis of eritadenine
Authors: Kamiya T. , Saito Y. , Hashimoto M. , Seki H.
Published: March 2009

A novel and convenient method for the synthesis of eritadenine (I) was established. Direct condensation of adenine and 2,3‐O‐isopropylidene‐D‐erythronolactone (II) under basic condition, followed by removal of the protecting group, afforded eritadenine (I) in fairly good yield, with accompany of a small amount of the N3‐isomer (VI). A similar reaction of adenine 1‐oxide gave exclusively eritadenine oxide (VII), which was catalytically reduced to give eritadenine (I). This procedure also provided pyrimidinyl derivatives (VIII, IX and X) corresponding to cytosine, uracil, and thymine.
Solvent effects on the tautomeric equilibria of 4,4/5,5‐disubstituted 4H/5H‐imidazol‐5/4‐ones
Authors: Edward J. T. , Lantos I.
Published: March 2009

The tautomerism of 4,4/5,5‐disubstituted 4H/5H‐imidazol‐5/4‐ones has been investigated by ir, uv, and pK studies. In nonpolar solvents the non‐conjugated tautomer predominates, but in polar solvents varying amounts of the conjugated tautomer may also be observed. The proportion of conjugated tautomer is increased by the presence of electron‐releasing groups at the 2‐position.
Infrared and mass spectra of purine and substituted dihydropurines
Authors: Connolly John S. , Linschitz Henry
Published: March 2009

Infrared spectra (potassium bromide) of purine, 7 (9)‐deuteriopurine, 6‐deuteriopurine, 8‐deuteriopurine and a number of substituted dihydropurines are presented. The latter compounds are the 6‐α‐hydroxyalkyl‐1,6 (or 3,6)dihydropurines formed by photoaddition of the respective alcohols to purine (4‐6). From the comparative spectra of purine and its mono‐deuterated derivatives, it is possible to make assignments of N‐H and N‐D stretching vibrations and tentative assignments of C‐H deformation modes. The spectra of the substituted dihydropurines show evidence of interesting hydrogen‐bonding interactions which are demonstrated most clearly in the distinct differences between the spectra of the diastereomeric purine‐ethanol adducts. Mass spectra of these compounds all indicate progressive scission of HCN molecules from the principal radical‐ion. In the case of the photo‐adducts, HCN scission is preceded by scission at the site (i.e. 6‐position) of alcohol addition to the purine ring.
A short synthesis of 4‐aryioxymethyl‐δ3‐chromenes and 3‐(β‐aryloxy)ethylbenzofurans
Authors: Majumdar K. C. , Thyagarajan B. S.
Published: March 2009

A direct and short route to the synthesis of 4‐aryloxymethyl‐δ3 ‐chromenes and 3‐(β‐aryloxy)‐ethylbenzofurans is described. Hydration of I,4‐diaryloxy‐2‐butynes with mercuric oxide and sulfuric acid affords, instead of a ketone, the cyclization product of the ketone. In three of the diaryloxy‐butynes studied, the corresponding aryloxyethylbenzofurans are formed. In no instance could the ketone be isolated from the hydration reaction.
The rearrangement of 4‐hydroxyeoumarin carbamates
Authors: Kraemer J. F. , Lira E. P.
Published: March 2009

Carbamate esters of 4‐hydroxycoumarin were prepared, and their base‐catalyzed and thermal rearrangement to 3‐(N‐substituted carbamoy])‐4‐hydroxycoumarins were studied. A mechanism for the rearrangement is proposed.
Mass spectra of some tropane and tropidine derivatives
Authors: Dewhurst J. Elton , Kaminski J. J. , Supple J. H.
Published: March 2009

Fragmentation patterns of tropane and tropidine derivatives have been shown to depend on the nature of the substituents. Unsaturation in the 6‐membered ring leads to preferential fragmentation of the two carbon bridge. When the 6‐membered ring is saturated and substituted with poor leaving groups (OH and CN) fragmentation of the 6‐membered ring is preferred.
An improved synthesis of tetrabromo‐2,1,3‐benzothiadiazoie
Authors: Bublitz D. E.
Published: March 2009

An improved synthesis of tetrabromo‐2,1,3‐benzothiadiazole using bromine and reduced iron powered is presented.
The synthesis of some 5‐methoxypyrimidine nucleosides
Authors: Stout M. G. , Robins R. K.
Published: March 2009

The synthesis of 5‐methoxyuridine (3), 5‐methoxycytidine (6), 1‐(2‐deoxy‐β‐D‐erythropento‐furanosyl)‐5‐methoxyuracil (14), 5‐methoxy‐1‐β‐D‐ribofuranosyl‐4‐thiopyrimidin‐2‐one (5), 1‐β‐D‐arabinofuranosyl‐5‐methoxycytosine (12), 1‐β‐D‐arabinofuranosyl‐5‐methoxyuracil (8) and 1‐β‐D‐arabinofuranosyl‐5‐methoxy‐4‐thiopyrimidin‐2‐one (11) have been accomplished. Both3and14were synthesized by alkylation of 2,4‐bis(trimethyIsilyI)‐5‐methoxyuracil (1) with the appropriately blocked halosugars. Synthesis of the corresponding 5‐methoxy‐1‐β‐D‐arabinofuranosyl derivatives was accomplished through the intermediate 2,2 ‐anhydro‐1‐β‐D‐arabinofuranosyl‐5‐methoxyuracil (7). The cytosine and 4‐thiouracil derivatives in both the arabino‐ and ribo‐ series were prepared by thiation followed by amination.
Spectra and photolysis of the 1‐oxides of the pyridinecarboxylic acids and pyridinecarboxamides
Authors: Caswell Lyman R. , Lee Florence C. , Creagh Linda T.
Published: March 2009

The ultraviolet absorption spectra of aqueous and alcoholic solutions of the pyridinemono‐carboxylic acids and amides, of the vicinal pyridinedicarboxylic acids, and of the 1‐oxides of these compounds, were measured and qualitatively interpreted. The photolysis of the 1‐oxides in aqueous solution resulted principally in their deoxygenation. Photolysis of picolinamide 1‐oxide also gave a rearrangement product, 1‐formyl‐2‐pyrrolecarboxamide. The photolyses of the 2‐ and 4‐monosubstituted 1‐oxides were somewhat faster than those of the 3‐substituted 1‐oxides. The experimental results are discussed in terms of possible hydrogen‐bonding effects.
Cyclic hydroxamic acids derived from quinazoliue
Authors: Schapira Celia B. , Lamdan Samuel
Published: March 2009

The action of various acylating agents on 2‐aminobenzohydroxamic acid afforded 3‐hydroxy‐4(3H)quinazolinones (hydroxamic acids) as well as several ethers and esters from them were prepared and their spectroscopic properties analyzed. Secondary amines, as well as one equivalent of alkali, on 2‐halomethyl‐3‐hydroxy‐4(3H)quinazolinone lead to the formation of a dimer(XI). In this respect the behaviour of secondary amines is different from that of primary amines. Some new 3‐hydroxy‐2‐4(1H,3H)‐quinazolidinediones are described.
Synthesis and structure of some asymmetrically substituted furoxans. I
Authors: Gasco A. , Mortarini V. , Ruà G. , Nano G. M. , Menziani E.
Published: March 2009

From the mixture of isomeric esters obtained by heating 3‐methy 1‐4‐furoxancarboxylie acid ethyl ester, some furoxan derivatives have been prepared; their structures were assigned on the basis of nmr spectroscopy.