bluuebunny/crossref_metadata_2025_split huggingface dataset:
A novel rearrangement of 1‐(2‐aminoaryl)imidazoles
Authors: Lampe John W. , Di Meo Susan V. , Traina Joseph A. 
Published: March 2009

Abstract6‐Ethyl‐2,4‐bis(1H‐imidazol‐1‐yl)pyrimidin‐5‐amine was found to undergo a novel rearrangement in the presence of acetic anhydride. The structure of the rearrangement product was deduced using a combination of one‐ and two‐dimensional nmr methods. Confirmation of the structure was obtained by unambiguous synthesis of a reduced analog and establishment of the identity of this material with material prepared by reduction of the rearrangement product. Examination of three related cases indicated that the rearrangement process is significant only when both positions adjacent to the aryl amino group are substituted.
Reaction of 5‐acetyl‐10,11‐didehydro‐5H‐dibenz[b, f]azepine with pyrrole, N‐methylpyrrole, imidazole and N‐methylimidazole: Cycloaddition versus michael addition
Authors: Bennett Robert A. , Cann Michael C. 
Published: March 2009

AbstractReaction of 5‐acetyl‐10‐bromo‐5H‐dibenz[b, f]azepine 1 with potassium t‐butoxide results in the reactive intermediate 5‐acetyl‐10,11‐didehydro‐5H‐dibenz[b, f]azepine (2). The intermediate 2 reacts with N‐methylpyrrole to give a mixture of the Michael addition adduct 10‐(2‐N‐methylpyrrolyl)‐5H‐dibenz[b, f]azepine (9) and the Diels‐Alder/retro Diels Alder adduct 8H‐(N‐methylpyrrolo[3,4‐d]dibenz[b, f]azepine (8a). Reaction of 2 with pyrrole gives a mixture of two Michael addition adducts 10‐(1‐pyrrolyl)‐5H‐dibenz[b, f]azepine (16) and 10‐(2‐pyrrolyl)‐5H‐dibenz[b, f]azepine (18). Reaction of 2 with imidazole results in the Michael addition adduct 10‐(1‐imidazolyl)‐5H‐dibenz[b, f]azepine (21).
Enzymatic resolution of 4‐methyl‐, 4‐phenyl‐ and 6‐phenyltetrahydro‐2H‐pyran‐2‐one using esterases
Authors: Izumi Taeko , Tamura Futoshi , Akutsu Mitsuyo 
Published: March 2009

AbstractEnantioselective hydrolysis of racemic tetrahydro‐2H‐pyran‐2‐ones (δ‐valerolactones) using esterase resulted in the formation of optically active (R)‐4‐methyl‐, (R)‐4‐phenyl‐ or (R)‐6‐phenyltetrahydro‐2H‐pyran‐2‐ones and the corresponding (S)‐8‐hydroxypentanoic acid derivatives.
Synthesis of imidazo[4,5‐c]pyridines with a trifluoromethyl group at C‐4 and/or C‐6
Authors: Gautam Rakesh K. , Fujii Shozo , Nishida Masakazu , Kimoto Hiroshi , Cohen Louis A. 
Published: March 2009

AbstractThermal condensation of histamine with trifluoroacetaldehyde gives 4‐(trifluoromethyl)spinacamine and subsequent dehydrogenation with selenium dioxide leads to 4‐(trifluoromethyl)‐1H‐imidazo[4,5‐c]pyridine (42%). Fluorination with sulfur tetrafluoride of L‐spinacine, obtained from the condensation of L‐histidine with formaldehyde, affords 6‐(trifluoromethyl)spinacamine, which can be converted to 6‐(trifluoromethyl)‐1H‐imidazo[4,5‐c]pyridine with selenium dioxide (49%). Application of the sequential reactions to 4‐(trifluoro‐methyl)‐L‐spinacine gives 4,6‐bis(trifluoromethyl)‐1H‐imidazo[4,5‐c]pyridine. Dehydrogenation of the tetrahydropyridine ring also occurred during the fluorination with sulfur tetrafluoride.
The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 14. 14‐methylbenzo[h]naphtho‐[1′2′:4,5]thieno[2,3‐c][1,6]naphthyridine
Authors: Musmar M. J. , Castle Raymond N. 
Published: March 2009

AbstractBenzo[h]naphtho[1′2′:4,5]thieno[2,3‐c][1,6]naphthyridine, a novel polycyclic heterocyclic ring system, has been synthesized as the 14‐methyl derivative 8 in four steps from known intermediates. The structure of 8 is supported by assignment of the proton and the protonated carbon atoms by 2D‐nmr techniques (COSY and a carbon‐hydrogen one‐bond coupling experiment).
Synthesis and prototropic tautomerism of 1‐n‐alkyl‐3‐methyl‐4‐nitroso‐5‐pyrazolones
Authors: Bartulín I. , Belmar I. , Gallardo H. , León G. 
Published: March 2009

AbstractNitrosation at C‐4 of 1‐n‐alkyl‐3‐methyl‐5‐pyrazolones is achieved in about 50% yield with sodium nitrite in hydrochloric acid medium. A tautomeric equilibrium in solution with a proton moving from the OH at C‐5 to N‐2 in the nitrosated pyrazolones is proposed.
Heterocyclic compounds studies. Dynamic 13C NMR investigation and crystal structure of 3‐hydroxy‐1,5‐benzoxathiepine
Authors: Cerioni Giovanni , Floris Costantino , Marongiu Giaime , Navarra Gabriele , Sotgiu Francesca 
Published: March 2009

Abstract1‐5‐benzoxathiepine compounds are a novel class of heterocyclic rings that present interesting properties as central nervous system depressants. With the aim to contribute to the elucidation of the structure‐activity relationship of this class of compounds we report a structural study of the 3‐hydroxy‐1,5‐benzoxathiepine both in solution and in the solid state. Studies by dynamic 13C‐nmr in solution show that three conformations are possible for the oxathiepin ring. A unique chair conformation characterizes the atoms in the oxathiepine ring of the crystallized molecule. The crystal structure was solved by direct methods. Values of bond distances and angles are within the expected range.
Synthesis of pyrazolo[1,5‐a]pyridines and pyrazolo[1,5‐c]pyrimidines by reaction of heterocyclic amidrazones with 1,3‐dicarbonyl compounds
Authors: Köckritz Peter , Riemer Beate , Michler Anke , Hassoun Ahmed , Liebscher Jürgen 
Published: March 2009

Abstract1,3‐Dicarbonyl compounds 2 react with 1‐amino‐2(1H)‐pyridin‐2‐imines or 1‐amino‐2(1H)‐pyrimidin‐2‐imines 1 giving new pyrazolo[1,5‐a]pyridines or pyrazolo[1,5‐c]pyrimidines 5 respectively by addition, oxidation and condensation. Isolation of an intermediate 3 shows that surprisingly the addition of the CH acidic 1,3‐dicarbonyl compound to position 6 of the pyrimidine 1 is the initial step.
Preparation, structure, and reactivity of 1,3,4,6‐tetrakis‐(isopropylthio)thieno[3,4‐c]thiophene‐palladium complex with tetracyanoethylene
Authors: Tsubouchi Akira , Nakamura Naomi , Sugimoto Akira , Inoue Hiroo , Adachi Tomohiro 
Published: March 2009

AbstractThe reaction of 1,3,4,6‐tetrakis(isopropylthio)thieno[3,4‐c]thiophene (1) with the palladium complex Pd2(dba)3CHCl3 (dba = dibenzylideneacetone) and tetracyanoethylene (TCNE) gave a new palladium complex in which two isopropylthio groups of 1 and the double bond of TCNE were trigonally coordinated to palladium. The X‐ray analysis revealed the electron donation from palladium to TCNE, leading to a lengthening of the CC double bond in TCNE and distortion of TCNE from planarity. The radical cation of 1 and the radical anion of TCNE were detected by ESR spectroscopy in methylene dichloride solution of the complex, although the radical content was estimated from the paramagnetic susceptibility to be less than 1%. The reaction of the complex with aniline gave the same product as that in the reaction of the radical cation of 1 with aniline.
NMR spectra and conformational analysis of some 4,5‐dihydro‐s‐triazolo[3,4‐d][1,5]benzothiazepine derivatives
Authors: Ambrogi Valeria , Grandolini Giuliano , Perioli Luana , Kajtàr‐Peredy Maria , Radics Lajos 
Published: March 2009

AbstractHigh field 1H and 13C nmr spectra of a series of 1‐substituted‐4,5‐dihydro‐s‐triazolo[3,4‐d][1,5]benzothiazepine derivatives have been recorded. These have shown that, unless X = H or O, the molecules occur as a mixture of two slowly interconverting conformers at ambient temperatures. Variable temperature nmr experiments disclosed that the energy barrier to interconversion varies with the size of the substituent X located at position 1 of the fused s‐triazole ring.
Synthesis of 9‐(trifluoromethyl)pyrido[1′,2′:1,2]‐imidazo[4,5‐b]quinoxalines
Authors: Iwata Satoru , Sakajyo Mitsumasa , Tanaka Kiyoshi 
Published: March 2009

Abstract9‐(Trifluoromethyl)pyrido[1′,2′:1,2]imidazo[4,5‐b]quinoxalines (9‐CF3‐PIQs) were obtained from the cyclization of 2‐amino‐3‐chloro‐6‐(trifluoromethyl)quinoxaline (1a) with some substituted pyridines. 3‐[2‐(4‐Pyridyl)ethenyl]‐9‐CF3‐PIQ, one of thus obtained 9‐CF3‐PIQs, cyclized with another molecule of 1a to produce the dihydro bis‐PIQ‐ethene derivative.
Conversion of 1‐benzyl‐4‐aminotetrahydropyridine‐3‐carboxylic acid methyl ester to antithrombotic pyrido[4,3‐d]pyrimidine‐2,4‐diones and to (2‐oxotetrahydropyrimidin‐4‐ylidene)acetic acid methyl esters
Authors: Furrer H. , Wagner R. , Fehlhaber H.‐W. 
Published: March 2009

Abstract6‐Benzyl‐3‐methyl‐5,6,7,8‐tetrahydro‐1H‐pyrido[4,3‐d]pyrimidine‐2,4‐dione 2, a representative of new antithrombotic compounds with favourable cerebral and peripheral effects has been synthesized from enamine 1 in good yield by two methods. The thermal fusion of 1 with ureas gave the pyrido[4,3‐d]‐pyrimidine‐2,4‐diones 5a, 2 and 5b and unexpectedly the esters 6 and 7. The structure of 6 was deduced from its spectroscopic properties and was proven by ozonolysis to cleavage products 9 and 10 and by oxidative hydrolysis to pyrimidin‐2‐one 13. The (Z)‐configured 6 was converted to (E)‐configured 7 by methylation. The products 5a, 5b and 5c were synthesized by independent methods. Hydrogenolysis of 2 led to the secondary amine 15 which was alkylated to the base of 16.
Synthesis of new guanidine derivatives from 2′,3′,4′,9′‐tetrahydrospiro[piperidine‐4,1′‐[1H]pyrido[3,4‐b]indole]
Authors: Domány Gy. , Gizur T. , Barta‐Szalai G. , Schön I. , Szántay Cs. , Hegedüs B. 
Published: March 2009

AbstractThe reaction of the isothiourea derivative 2 with methylaminc or pyrrolidine resulted in guanidines 3a‐3b. Using hydrazine under the same conditions the tetrazole derivative 4 was obtained. On reacting 2 with piperidine, morpholine, methylhydrazine, phenylhydrazine, hydroxylamine or sodium hydroxide, cycliza‐tion took place leading to the novel 4‐cyanimino‐1,2,3,4,6,7,12,12b‐octahydro‐3,12b‐ethanopyrim‐ido[1′,6′:1,2]pyrido[3,4‐b]indole (5). Some structural aspects of 5 and other model compounds were analysed mainly by 13C nmr spectroscopy.
Lewis acid assisted cyclization of arylcyanoguanidines to 2,4‐diaminoquinazolines
Authors: Jones Michael L. , Kuyper Lee F. , Styles Virgil L. , Caddell J. Marc 
Published: March 2009

AbstractThe mild preparation of N‐cyano‐N‐(1‐H‐indol‐5‐yl)guanidine and its cyclization to 1,3‐diamino‐7H‐pyrrolo[3,2‐f]quinazoline is described. Whereas previously reported methods of cyclization employed high temperatures to effect ring closure, we found that certain Lewis acids, such as boron trifluoride etherate, induce cyclization at moderate temperatures.
Synthesis of 2‐(1‐chloroalkyl)‐1,3‐benzodithioles and 2‐alkylidene‐1,3‐benzodithioles
Authors: Bellesia Franco , Boni Monica , Ghelfi Franco , Pagnoni Ugo M. 
Published: March 2009

AbstractBoron trifluoride promoted transdithioacetalization of α‐chloroacetals with 1,2‐benzodithiol affords good yields of 2‐(1‐chloroalkyl)‐1,3‐benzodithioles, which dehydrochlorinates very satisfactorily to the corresponding 2‐alkylidene‐1,3‐benzodithioles.
Syntheses of substituted 1‐methyl‐2‐(1,3,4‐thiadiazol‐2‐yl)‐4‐nitropyrroles and 1‐methyl‐2‐(1,3,4‐oxadiazol‐2‐yl)‐4‐nitropyrroles
Authors: Firoozi F. , Javidnia K. , Kamali M. , Fooladi A. , Foroumadi A. , Shafiee A. 
Published: March 2009

AbstractStarting from readily available ethyl‐4‐nitropyrrole‐2‐carboxylate (1), substituted 1‐methyl‐2‐(1,3,4‐thiadiazol‐2‐yl)‐4‐nitropyrroles and 1‐methyl‐2‐(1,3,4‐oxadiazol‐2‐yl)‐4‐nitropyrroles were prepared. The reaction of 1 with diazomethane gave ethyl 1‐methyl‐4‐nitropyrrole‐2‐carboxylate (2). Reaction of compound 2 with hydrazine hydrate afforded the corresponding hydrazide 3. The reaction of 3 with formic acid yielded 1‐(1‐methyl‐4‐nitropyrrole‐2‐carboxyl)‐2‐(formyl)hydrazine (7). Refluxing of the latter with phosphorus pentasulfide in xylene yielded compound 6 in 40% yield. Reaction of compound 7 with phosphorus pentoxide afforded compound 9. Reaction of compound 3 with 1,1′‐carboxyldiimidazole in the presence of triethylamine yielded 2‐(1‐methyl‐4‐nitro‐2‐pyrrolyl)‐1,3,4‐oxadiazoline‐4(H)‐5‐one (11). Refluxing compound 3 with cyanogen bromide in methanol gave compound 12. Compound 13 could be obtained through the reaction of compound 3 with carbon disulfide in basic medium. Alkylation of compound 13 afforded the correspanding alkylthio derivative 14. Reaction of 1‐methyl‐4‐nitropyrrole‐2‐carboxylic acid (15) with thiosemicarbazide and phosphorus oxychloride gave 2‐amino‐5‐(1‐methyl‐4‐nitro‐2‐pyrrolyl)‐1,3,4‐thiadiazole (16). Sandmeyer reaction of compound 16 yielded 2‐chloro‐5‐(1‐methyl‐4‐nitro‐2‐pyrrolyl)‐1,3,4‐thiadiazole (17). Refluxing of the latter with thiourea afforded 2‐(1‐methyl‐4‐nitro‐2‐pyrrolyl)‐1,3,4‐thiadiazoline‐4(H)‐5‐thione (18). Alkylation of compound 18 gave the corresponding alkylthio derivative 19. Oxidation of the latter with hydrogen peroxide in acetic acid yielded 2‐(1‐methyl‐4‐nitro‐2‐pyrrolyl)‐5‐methylsulfonyl‐1,3,4‐thiadiazole (20).
Synthesis and resolution of 2‐arylalkyl‐2‐(tetrazol‐5‐yl)‐N‐arylalkyl‐carboxamides. A new class of chiral sterically hindered tetrazole derivatives
Authors: Moriarty Robert M. , Levy Stuart G. 
Published: March 2009

AbstractChiral, racemic 2‐arylalkyl‐2‐(tetrazol‐5‐yl)‐N‐arylalkylcarboxamides 3 were conveniently prepared from ethyl cyanoacetate in four steps. The synthetic methodology developed is a facile way of introducing bulky substituents into a peptide‐like framework, affording intermediate α‐arylalkyl‐α‐amidonitriles. These nitriles were sufficiently activated to give, upon treatment with ammonium azide in dimethylformamide at 145° for twenty‐four to thirty hours, the corresponding tetrazoles in good yields. It has been determined that an optically pure α‐arylalkyl‐α‐amidonitrile epimerized to give diastereomeric products under the above conditions. A procedure for the fractional crystallization of the (S)‐(‐)‐α‐methylbenzylamine salts 4 of the tetrazoles to give the optically enriched tetrazoles 5 was also developed.
Preparation of trifluoromethylated pyrazoles and 1,4‐thiazine 1,1‐dioxides from trifluoromethylated sulfone derivatives
Authors: Takahashi Masahiko , Chigira Keiko 
Published: March 2009

AbstractTrifluoromethylated sulfones, 3‐amino‐2‐arylsulfonyl‐4,4,4‐trifluoro‐3‐hydroxybutanenitrile (3) and 3‐(aroylmethyl)sulfonyl‐1,1,1‐trifluoropropane‐2,2,‐diols 12, were prepared and cyclized to 4‐arylsulfonyl‐5‐trifluoromethyl‐3‐hydrazinopyrazoles 9 and 5‐arylsulfonyl‐3‐trifluoromethyl‐3‐hydroxy‐2,3‐dihydro‐4H‐1,4‐thiazine 1,1‐dioxides 13, respectively.
Syntheses of substituted 1‐(2‐phenethyl)pyrazoles
Authors: Nazarinia M. , Sharifian A. , Shafiee A. 
Published: March 2009

AbstractAlkylation of 3‐methylpyrazole with 2‐phenethyl p‐toluenesulfonate gave 3‐methyl‐1‐(2‐phenethyl)pyrazole (2a) and 5‐methyl‐1‐(2‐phenethyl)pyrazole (3a) in low yield. Reaction of 5‐chloro‐1,3‐dimethylpyrazole (5) with substituted‐benzaldehydes afforded compounds 7. Reduction of the latter afforded compound 2 in high yield. Compound 3 could be obtained from the reaction of substituted‐2‐(phenethyl)hydrazine hydrochloride 9 with acetoacetaldehyde dimethylacetal in moderate yield.
Studies on the reactivity and structure of phenyl 7‐fluoro‐4‐chromone‐3‐sulfonate
Authors: Löwe Werner , Bischoff Susan , Weber Manuela , Perpetuo Genivaldo , Luger Peter 
Published: March 2009

AbstractThe new, fluorinated benzoxathiinopyrazole 4 and the hitherto unknown fluorinated benzoxathiinodihydropyridine 5 can be produced by reacting the title compound 1 with cyanoacetic hydrazide (3) in the presence of sodium acetate. The structures of the compounds 4 and 5 were confirmed with the help of spectroscopic techniques, and their respective paths of formation have been discussed. The structure of the ester 1 was extensively studied by single crystal X‐ray analysis, then compared with that of the unfluorinated phenylsulfonate 2.
A facile synthesis of 3‐alkoxy phthalides by the palladium catalyzed carbonylative cyclization of o‐bromobenzaldehyde
Authors: Shim Sang Chul , Lee Dong Yub , Jiang Li Hong , Kim Tae Jeong , Cho Sung‐Dong 
Published: March 2009

AbstractThe palladium catalyzed carbonylative cyclization of o‐bromobenzaldehyde 1 in alcoholic solution gave 3‐alkoxyphthalides 3a‐e in 61–85% isolated yields via intramolecular cyclization induced by the coordinated formyl group on the palladium.
Amino acids in the synthesis of heterocyclic systems. Synthesis of γ‐(5‐(1,2,4‐Triazinylidene))‐α,β‐dehydro‐α‐amino acid derivatives and 6H‐pyrido[1,2‐d][1,2,4]triazin‐6‐ones
Authors: Stanovnik Branko , Tišler Miha , Čopar Anton 
Published: March 2009

Abstract5‐(1,2,4‐Triazinyl) substituted enamines 3 react with 5(4H)‐oxazolones 4 in acetic anhydride to give acetylated products 5, while in toluene‐acetic acid mixture nonacetylated products 9 are formed. Both types of products were isolated as (E,Z) mixtures. Compounds 5 and 9 rearrange into 6H‐pyrido[1,2‐d]‐[1,2,4]triazin‐6‐ones 12 by heating in formic acid or in xylene, respectively. Compounds 5 are transformed in the presence of nucleophiles, such as sodium alkoxides or sodium amides via anionic form 10 into corresponding esters 13 and amides 14 of γ‐(5‐(1,2,4‐triazinylidene)) substituted derivatives of α‐amino‐2‐butenoic acid, which exist in 2‐(Z),4‐(Z) form.
Diels‐alder reactions of 2‐ and 3‐vinyl‐1‐(phenylsulfonyl)pyrroles
Authors: Xiao Dong , Ketcha Daniel M. 
Published: March 2009

AbstractRegioselectively produced 2‐ and 3‐acetyl‐1‐(phenylsulfonyl)pyrroles can be reduced to the corresponding alcohols and subsequently dehydrated to afford N‐protected vinylpyrroles. These remarkably stable vinylpyrroles can then serve as heterodienes in [4 + 2] cycloaddition reactions with electron deficient dienophiles to afford tetrahydroindole derivatives.
The vilsmeier reaction in the synthesis of 3‐substituted [1]benzopyrano[4,3‐b]pyridin‐5‐ones. An unusual pyridine ring closure
Authors: Heber D. , Ivanov I. C. , Karagiosov S. K. 
Published: March 2009

AbstractStarting from 4‐chlorocoumarin‐3‐carbaldehyde (1) and Wittig phosphoranes 2a‐d the title compounds 6a‐c have been synthesized via a four‐step sequence. The intermediate 4‐alkylamino‐3‐vinylcoumarins 5a‐k have been prepared by the reaction of 4‐chloro‐3‐vinylcoumarins 3a‐d with primary amines 4a‐h. The coumarin derivatives 5 (except 5k) underwent an unusual pyridine ring closure under Vilsmeier conditions to form the benzopyrano[4,3‐b]pyridines 6. When the aminoaldehydes 7 were treated with the Wittig reagent 2b the fused N‐alkyl‐2(1H)‐pyridinones 8 have been obtained as expected.
Synthesis of dibenzocrown ethers with pendant thioamide groups
Authors: Jang Youngchan , Bartsch Richard A. 
Published: March 2009

AbstractThe synthesis of eighteen crown ether compounds with pendant thioamide, N‐alkylthioamide, and N,N‐dialkylthioamide groups is reported. The new crown ether compounds are obtained by one‐step reactions from the corresponding sym‐dibenzo‐16‐crown‐5‐oxyacetamides and sym‐(propyl)dibenzo‐16‐crown‐5‐oxyacetamides with Lawesson's reagent.
A facile synthesis and spectral (ir, 1H, 13C, 31P nmr) studies of 2,10‐dichloro‐6‐aryloxy‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐sulfides
Authors: Devendranath Reddy C. , Mallikarjuna Reddy P. , Ramasubba Reddy D. , Nagalakshmamma M. , Anuradha K. , Raju C. Naga , Berlin K. Darrell , Couch Kevin M. , Tyagi Sameer 
Published: March 2009

AbstractThe synthesis of new 2,10‐dichloro‐6‐aryloxy‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐sulfides 4 was achieved in two steps with high yields from the simple materials 5,5′‐dichloro‐2,2′‐dihydroxydiphenyl‐methane (1) and thiophosphoryl chloride (2) which produced the key intermediate 2,6,10‐trichloro‐12H‐dibenzo[d,g][1,3,2]dioxaphosphocin 6‐sulfide (3). Treatment of 3 with substituted phenols under phase transfer catalytic (PTC) conditions led to members of 4. Long range coupling [5J(P,H) = 3.6 Hz] was observed between phosphorus and one of the bridged methylene protons in 4. A 13C nmr analysis revealed 2J(P,O,C), 3J(P,O,C) 4J(P,O,C) and 5J(P,O,C) couplings. All 31P nmr chemical shifts for thirteen members of these new heterocycles are reported for the first time. The nmr data are not totally definitive to confirm a boat‐chair as the major conformer for the central eight‐membered dioxaphosphocin ring, but such a conformer is tentatively suggested as favored.
A numerical measure of the degree of oxidation (DOX) of an organic molecule, with special attention to heteroatoms and heterocyclic compounds
Authors: Klemm L. H. 
Published: March 2009

AbstractThe degree of oxidation (DOX) of an organic compound CnHmEp, where E is any one or more of eleven elements more electronegative than hydrogen, is defined with respect to an alkane CnH2n+2 (DOX = 0) as a reference, One can calculate DOX either from the molecular or the structural formula of the compound by the relationship DOX = DU + p, where DU is the degree of unsaturation (i.e. index of hydrogen deficiency) in the molecule. The concept is developed for E is oxygen, and is extended to other chalcogens, as well as to halogens, nitrogen, phosphorus, and arsenic. Particular examples of heterocyclic compounds are considered. It is noted that addition of a simple hydride of E to an organic compound or elimination of the hydride from CnHmEp leaves DOX unchanged.
The synthesis of several novel triazine ring hydrolysis products of n‐[[(4‐methoxy‐6‐methyl‐1,3,5‐triazin‐2‐yl)amino]carbonyl]‐2‐(3,3,3‐trifluoropropyl)benzenesulfonamide
Authors: Heard Nina E. , Overman Monica C. 
Published: March 2009

AbstractThe syntheses of four hydrolysis products isolated from environmental studies on the title compound are reported. Spectral comparison of these synthetic standards with study isolates provided proof for sulfonyl urea intact triazine ring hydrolysis.
Propenethioamides in the synthesis of heterocyclic systems. Synthesis of pyrrole and 1,4‐thiazepine derivatives
Authors: Cocco Maria Teresa , Congiu Cenzo , Onnis Valentina 
Published: March 2009

AbstractThe reaction of propenethioamides 1 with bromoketones 2 and 3 led in acidic medium to the formation of 1,4‐thiazepines 6 and 7. The pyrrole derivatives 4 and 5 were obtained by reaction of 1 with 2 and 3 in basic medium.
The synthesis of cis‐6,12‐Diaryl‐6H,12H‐dibenzo[b,f][1,5]dithiocin‐6,12‐imine and cis‐6,12‐Diphenyl‐6,12‐epoxy‐6H,12H‐dibenzo[b,f][1,5]dithiocin
Authors: Brieaddy Lawrence E. , Donaldson Kelly H. 
Published: March 2009

AbstractWhen treated with concentrated hydrochloric acid or heated beyond its melting point, the versatile thioimine 2 2‐mercaptobenzhydrylidenamine was unexpectedly converted to the title ring system. Also, this imine can be converted to 3‐phenyl‐1,2‐benzisothiazoles by prolonged exposure to air.
Sommelet‐hauser rearrangement of an ammonium ylide derived from the HIV‐1 reverse transcriptase inhibitor nevirapine
Authors: Klunder Janice M. 
Published: March 2009

AbstractFunctionalization at the 3‐position of the dipyridodiazepinone nevirapine (1) has been accomplished by Sommelet‐Hauser rearrangement of an ylide derived from 1. Treatment of N‐cyanomethylpyrrolidinium salt 4 with potassium tert‐butoxide in a mixture of dimethylsulfoxide and tetrahydrofuran at −10°, followed by acid hydrolysis, afforded a mixture of compounds 5 and 6 in a ratio of 1:1.8. Upon treatment of 4 with sodium amide in liquid ammonia, 5 and 6 were obtained in a ratio of 1.5:1 and a combined yield of 83%. Compound 5 is the desired product resulting from Sommelet‐Hauser rearrangement of 4, whereas 6 derives from competing Stevens rearrangement and intramolecular cyclization of the aldehyde produced upon hydrolysis. Baeyer‐Villiger oxidation of 5 afforded the 3‐hydroxy derivative 2, a recently identified metabolite of nevirapine.