bluuebunny/crossref_metadata_2025_split huggingface dataset:
Products from lactones and hydrazines: Hydroxyalkanohydrazides and pyrazolidones
Authors: Allen C. F. H. , Magder Edna Weismann 
Published: March 2009

AbstractSaturated aliphatic lactones and dihydrocoumarins have been characterized by the formation of their crystalline 1:1‐adducts (hydroxyalkanohydrazides) with hydrazine hydrate. A new procedure, which involves the use of azeotropic distillation to remove the water present, greatly facilitates the reaction by reducing the time required. Three macrocyclic lactones, that did not react in either of two short procedures, readily formed the same type of 1:1‐adducts after several hours of refluxing of the components in alcoholic solution. The unsaturated macrocyclic lactone gave two products of cleavage; one was the expected ω‐hydroxyalkenohydrazide, but the other was its saturated analog, in which the double bond had been reduced by the excess hydrazine employed. β‐Lactones are a special case, requiring variations in conditions; the yield of the simplest adduct was more than doubled by a new procedure. In one instance products in which the lactone ring had been opened in both possible ways were obtained for the first time. A “stream‐lined extracter” was useful with the low melting adducts. Coumarins themselves gave either 1:2 adducts or pyrazolidones. The latter could also be prepared from the adducts.A study of 4‐hydroxybutanohydrazide in a mass spectrometer showed that both γ‐butyro‐lactone and 5‐methyl‐3‐pyrazolidone are thermal products. Pure 5‐methyl‐3‐pyrazolidone has now been isolated from the syrupy reaction product of ethyl crotonate and hydrazine, It has been converted to benzylidene derivatives; spectral data of the latter are consistent with their polarized structures.
Benzacridines VI.. Functional derivatives of 5,6‐dimethylbenz[c]acridine
Authors: Cromwell Norman H. , Nielsen Lawrence A. 
Published: March 2009

Abstract5,5‐Dimethyl‐5,6‐dihydrobenz[c]acridone has been synthesized by three different routes: a, from a condensation of anthranilic acid with 4,4‐dimethyl‐1‐tetraIone; b, by a catalytic hydrogenation of 2‐(o‐nitrobenzal)‐4,4‐dimethyl‐1‐tetralone oxide followed by an acid catalyzed cleavage of the oxide ring and closure of the nitrogen heterocyclic ring; c, a multi‐step process starting with 7‐carboxy‐5,5‐dimethyl‐5,6‐dihydrobenz[c]acridine. Several new functional derivatives of both 5,5‐dimethyl‐5,6‐dihydrobenz[c]acridine and of 5,6‐dimethylbenz[c]acridine were also produced for biological study by others.
Ellipticine analogs: Oxygen and sulfur isosteres
Authors: Fujiwara Allan N. , Acton Edward M. , Goodman Leon 
Published: March 2009

AbstractOxaellipticine has been synthesized from 1,4‐dimethyldibenzofuran, by converting it to the 2‐aldehyde, forming the Schiff's base with aminoacetaldehyde diethyl acetal, and cyclizing this with 105%superphosphoric acid. Alternatively, tetrahydrodimethyldibenzofuran was formylated mainly at the 3‐position, and the 3‐(2‐nitrovinyl) derivative of the 3‐aldehyde, by hydride reduction, then Bischler‐Napieralski cyclization of the 3‐(2‐formamidoethyl) derivative, afforded hexahydrooxaellipticine, which could be aromatized only in poor yield. Isooxaellipticine, the pyrido‐A' positional isomer, was similarly prepared from the nitrovinyl derivative of 1,4‐dimethyl‐2‐dibenzofurancarboxaldehyde, through cyclization of the formamidoethyl intermediate and aromatization of the dihydro product. Likewise, isothiaellipticine was obtained from 1,4‐dimethyl‐2‐dibenzothiophenecarboxaldehyde.
The mass spectra of formycin, formycin B and showdomycin carbon linked nucleoside antibiotics
Authors: Townsend Leroy B. , Robins Roland K. 
Published: March 2009

AbstractThe mass spectra of the nucleoside antibiotics formycin (I), formycin B (II) and their heterocyclic aglycons (7‐aminopyrazolo[4,3‐d]pyrimidine and pyrazolo[4,3‐d]‐7‐pyrimidone) have been studied utilizing high resolution mass spectroscopy. The major electron‐impact fragmentation pattern exhibited by the heterocyclic aglycons can be explained by the initial expulsion of hydrogen cyanide followed by decarbonylation or by loss of a second mole of hydrogen cyanide. There is a striking difference in the fragmentation pattern of these nucleoside antibiotics where the glycoside linkage is a C‐C bond as compared to nucleosides possessing a C‐N bond linkage. The base peak observed for formycin and formycin B occurred at B + 30 in direct contrast to the usual nucleosides where the B + 1 or B + 2 normally occurs as the predominant peak. This pattern suggests that such a carbon linked nucleoside should be readily identified by this means. The mass spectrum of showdomycin (3‐β‐D‐ribofuranosylmaleimide, III) was also determined and found to exhibit a similar parent peak at B + 30. This base + 30 peak has been assigned to the aglycon plus a protonated formyl group which results from fragmentation of the sugar. Mass spectrometry should prove very useful in the future structural elucidation of carbon linked nucleoside derivatives since these features (B + 30 and M‐103) may be considered diagnostic.
Perhaloketones XIX . Derivatives of benzo‐N‐heterocycles
Authors: Gilbert Everett E. 
Published: March 2009

AbstractA study was made of the behavior of imidazole and six benzo‐N‐heterocyclic compounds upon direct treatment with anhydrous and hydrated hexafluoro‐ and sym‐tetrafluorodichloroacetones. Two of the compounds did not react, and four gave addition compounds. Indole reacted with both ketones in the 3‐position. Heterocyclic precursors were made by reacting o‐phenylenediamine, o‐aminophenol, and o‐aminobenzenethiol with hexafluoroacetone hydrate, thus introducing the 2‐hydroxyhexafluoro‐2‐propyl moiety into the ring para to the amino group. A similar product was made from o‐phenylenediamine and tetrafluorodichloroacetone. These compounds were then converted to twenty‐eight heterocyclic derivatives. Four of the latter underwent haloform cleavage of the hydroxyhexahalopropyl group, a novel, but not widely applicable, preparative approach to the corresponding heterocyclic carboxylic acids.
Synthesis and reactions of 4,6‐dimethoxyindole, an unusual indole system
Authors: Brown Vernon H. , Skinner W. A. , Degraw Joseph I. 
Published: March 2009

AbstractA synthesis of 4,6‐dimethoxyindole is described. Formylation or oxalylation reactions gave substitution at position 7 rather than the usual 3‐substitution characteristic of other indoles. A synthesis of N,N‐dimethyl‐4,6‐dimethoxytryptamine is presented along with NMR data for 3 and 7‐substituted compounds in this series.
Preparation of bis‐pyrylium salts
Authors: Reynolds C. A. , Vanallan J. A. 
Published: March 2009

AbstractSix methods are described for the preparation of bis‐pyrylium salts: (1) treatment of 4,4′‐bi‐2‐flavene or 4‐(4H‐flav‐2‐en‐4‐yl)flavylium perchlorate with triphenylmethyl perehlorate; (2) reaction of an aromatic o‐hydroxyaldehyde and 1,4‐deacetylbenzene under acidic conditions; (3) reaction of o‐hydroxyacetophenone, 1,4‐diacetylbenzene, perchloric acid and acetic acid; (4) reaction of a 2‐ or 4‐methylpyrylium salt with 2‐ or 4‐pyrone in the presence of phosphorus oxychloride; (5) oxidation of a 1,2‐ethanediylidenebis‐flavene or ‐thiaflavene, a bis‐flavenylidene or ‐thiaflavenylidene, and a bis‐pyranylidene or ‐thiapyranylidene by means of cupric perchlorate; and (6) reaction of 4‐methylflavylium and ‐thiaflavylium perchlorate with bromine in acetic acid.
Alcoholation of the trifluoromethyl group. I. Ortho esters derived from 1‐ and 3‐trifluoromethylphenothiazines
Authors: Saggiomo Andrew J. , Asai Masaru , Schwartz Pauline M. 
Published: March 2009

AbstractThe preparation of 1‐trifluoromethylphenothiazine is reported. Methanolic basic hydrolysis of 1‐ and 3‐trifluoromethylphenothiazines to the corresponding ortho esters of phenothiazine‐carboxylic acids is described.
A study of the synthesis and some reactions of 3‐phenyl‐1,4‐benzothiazines
Authors: Wilhelm Max , Schmidt Paul 
Published: March 2009

AbstractCondensation of o‐aminothiophenol with 2‐bromoacetophenone yields 3‐phenyI‐1,4‐benzo‐thiazine hydrobromide, which upon treatment with alkali gave a mixture of 3‐phenyl‐2H‐1,4‐benzothiazine (VIIa) and 3‐phenyl‐4H‐1,4‐benzothiazine (VIIb). Catalytic hydrogenation led to rearrangement of the benzothiazine (VIIa) to 2‐phenyl‐2‐methyl‐2,3‐dihydrobenzothiazole (X), while reduction with lithium aluminium hydride resulted in 3‐phenyl‐2,3‐dihydro‐4H‐1,4‐benzothiazine (XVI). The latter was transferred to 3‐phenyl‐4‐aminoalkyl‐2,3‐dihydro‐4H‐1,4‐benzothiazines (XVII and XVIII).
Toxic chlorinated methanoisobenzofuran derivatives
Authors: Weil E. U. , Colson J. G. , Hoch P. E. , Gruber R. H. 
Published: March 2009

AbstractUpon treatment with alcoholic base, 1,4,5,6,7,7‐hexachloro‐5‐norbornene‐endo‐cis‐2,3‐dimethanol (1) yields a tricyclic ether (111) which is converted by sulfuric acid to two epimeric 4,6,7,8,8‐pentachloro‐octahydro‐4,7‐methanoisobenzofuran‐5‐ones (111 A & B). These relatively nontoxic isomers, upon introduction of two chlorine atoms α and α′ to the ether oxygen, yield two epimeric products of high toxicity to insects and mammals. These 1,3,4,6,7,8,8‐heptachloro‐octahydro‐4,7‐methanoisobenzofuran‐5‐ones (IV A & B) upon transannular dehydrochlorination yield a toxic tetracyclic ketone (VI A). Reduction of this ketone by lithium aluminum hydride affords an alcohol (VII) of similarly high insecticidal toxicity. Nuclear magnetic resonance and infrared spectra are presented as evidence for the indicated structures. Results of this study are interpreted as indicative of the regions of the molecule which are critical in regard to toxicity.
N‐polyfluoroalkyl aziridines
Authors: Thorn K. F. , Sweeny N. P. , Mcbrady J. J. 
Published: March 2009

AbstractAziridines add almost quantitatively and without ring opening to tetrafluoroethylene and chlorotrifluoroethylene to yield N‐polyfluoroalkyl aziridines. Physical properties, H1‐NMR, F19‐NMR and IR spectra of these compounds are reported, along with their susceptibility to undergo rearrangements catalyzed by electrophiles.
Substituted 1,3‐dihydro‐4H‐furo[3,4‐d]‐1,3‐benzodiazepin‐3‐ones: Synthesis and scope of the method
Authors: Venturella Vincent S. , Watson Edward J. 
Published: March 2009

AbstractThe preparation of a series of 1,3‐dihydro‐4H‐furo[3,4‐d]‐1,3‐benzodiazepiri‐3‐ones has been studied. This study and the compounds prepared tend to illustrate that the limiting factor in the scope of the synthetic method is similar to that noted generally in the Fisher indole synthesis. The lactone ring is relatively stable under a variety of conditions, and is believed to lend ease of formation to the ring system studied.
Cyclic acylimines and cyclic carbinolamides 1. 2‐azaphenaiones.
Authors: Warshawsky A. , Ben‐Ishai D. 
Published: March 2009

Abstract2‐Azaphenalone hydrochloride (VI), 2‐methyl‐1‐azaphenalonium chloride (XIV), 3‐phenyl‐2‐azaphenalone (XVIII) and 3‐phenyl‐2‐methyl‐2‐azaphenalonium chloride (XXI) were synthesized and their chemical and physical properties were studied. At room temperature they add weak nucleophiles (e.g., alcohols, amides) as well as compounds possessing active methylene groups. The methanol addition products (e.g., V) reacted thermally or in the presence of an acid catalyst with nucleophiles to give products identical with those obtained from the azaphenalone hydrochlorides.
A new linear notation system based on combinations of carbon and hydrogen
Authors: Skolnik Herman 
Published: March 2009

AbstractA new linear notation system is described which was designed to have a one‐to‐one correspondence with the chemical structures represented by the notations. Each notation is unique and unambiguous, yet simple and compatible with computer input and output characters. The symbols used in the notation system denote carbon in terms of bonds and attached hydrogen(s). The notation system is illustrated with acyclic, carbocyclic, and heterocyclic examples.
Pyranylidene iminium salts II. Iminium salts derived from pyrones, dialkylamides and phosphorus oxychloride
Authors: Vanallan J. A. , Petropoulos C. C. , Reynolds G. A. 
Published: March 2009

AbstractN,N‐Dialkylamides, pyrones, and phosphorus oxychloride react to give pyranylidene chloroiminium salts. The chlorine atom of these salts is readily displaced by nucleophiles to yield a variety of pyranylidene derivatives.
Chemistry of thienopyridines. VII. Mechanistic studies on the synthesis of thieno[2,3‐c] pyridine by thermolytic cyclization
Authors: Klemm L. H. , Mccoy D. R. , Shabtai J. , Kiang W. K. T. 
Published: March 2009

AbstractA study was made of the formation of thieno[2,3‐c]pyridine (1) from hydrogen sulfide and 4‐vinylpyridine in a flow system at 630°. 2‐(4‐Pyridyl)ethanethiol and bis‐2‐(4‐pyridyl)ethyl sulfide were found to be likely intermediates. Based on these studies, there was devised a two‐step practical preparative method for I (optimum overall yield 58%) which consists of preliminary conversion of 4‐vinylpyridine to benzyl 2‐(4‐pyridyl)ethyl sulfide and subsequent thermolysis (at 605°) of this substance.
Aromatic substitution of 4‐phenylisothiazole
Authors: Finley Joseph H. , Volpp Gert P. 
Published: March 2009

AbstractAromatic substitutions on 4‐phenylisothiazole by nitric acid, halogens, chlorosulfonic acid and acetic anhydride take place under relatively mild conditions to give predominantly para and ortho substitution on the benzene ring. By contrast, the 3‐isothiazolyl group has been shown to be meta directing. Several derivatives of 4‐phenylisothiazole are described.
Electron‐impact induced fragmentation of alkylthiopyridines. The extent of ring nitrogen involvement
Authors: King Kenneth F. , Hershenson Fred M. , Bauer Ludwig , Bell Charles L. 
Published: March 2009

AbstractThe fragmentation patterns obtained upon electron impact of 2‐, 3‐, and 4‐alkylthio‐pyridines were examined to determine the extent that the ring nitrogen is involved. The effect of the size of the alkyl group, as well as the ring position of the sulfide on the fragmentation of the methyl‐, ethyl‐, n‐propyl‐, n‐butyl‐ and t‐butylthiopyridines, is discussed. The mass spectrum of 2‐n‐octylthiopyridine is also recorded.The molecular ions decomposed with rupture of the bonds α, β, γ, and δ from the hetero‐aromatic ring. The molecular ions also exhibited the loss of alkenes via a number of mechanisms, notably the loss of Cn‐1 H2n from the alkyl group of 2‐alkylthiopyridines by a transition involving the rupture of a C‐C bond γ to the ring and the transfer of a proton on a carbon ϵ to the ring. The role of the pyridine sp2 nitrogen in this and other fragmentations is discussed. An elimination of HS radical is also observed in a number of these alkylthiopyridines.
Mannich and eschweiler‐clarke reaction of 1‐benzyl‐1,2,3,4‐tetrahydroisoquinolines. Studies on the syntheses of heterocyclic compounds. Part CCCXVIII
Authors: Kametani T. , Noguchi I. , Saito K. 
Published: March 2009

AbstractModified Mannich reactions of a number of 1‐benzyl‐1,2,3,4‐tetrahydroisoquinolines (Ia‐Ie) were attempted to afford the corresponding protoberberine derivatives (IIa‐IIe) in good yield. Treatment of both If and Ig with formalin under a variety of Mannich or Eschweiler‐Clarke conditions did not give the expected protoberberine derivatives IIf and IIg, but afforded the N‐methyl derivatives (VIIa) and (VIIb), respectively.
The synthesis of thiaolivacine and related compounds
Authors: Campaigne E. , Ashby John 
Published: March 2009

Abstract1,5‐Dimethylbenzothieno[2,3‐g]isoquinoline (thiaolivacine) has been prepared from the nitro‐vinyl derivative of 4‐methyl‐3‐dibenzothiophenecarboxaldehyde. Using the same aldehyde, 4‐des‐methylisothiaolivacine was prepared by formation of the Schiff's base with aminoacetaldehyde diethyl acetal followed by cyclization. Similar methods yielded the pyrido‐N‐isomer, 1‐des‐methylthiaolivacine, from 4‐methyl‐2‐dibenzothiophenecarboxaldehyde. The thiaolivacine parent unsubstituted ring system, benzothieno[2,3‐g]isoquinoline, was prepared from 2‐dibenzothio‐pheneearboxaldehyde by the aminoacetaldehyde approach, as was the corresponding oxygen analog, benzofuro[2,3‐g]isoquinoline, from 2‐dibenzofurancarboxaldehyde. The 100 MHz spectra of these fused isoquinolines are recorded and correlated.
The deactivating effect of a meta‐methoxy group in the methoxydechlorination of pyridine and pyrimidine derivatives
Authors: Forchiassin M. , Illuminati G. , Sleiter G. 
Published: March 2009

AbstractReactivity data and the activation parameters for the methoxydechlorination of some 2‐chloro‐4‐R‐pyridines and 4‐chloro‐6‐R‐pyrimidines have been determined. A methoxy group meta with respect to the reaction site is found to be deactivating as already observed in the quinoline series. This gives further support to the hypothesis that in N‐heteroaromatic systems a conjugative interaction of an electron‐releasing substituent with the aza group (s) is a factor in modifying the nucleophilic reactivity as predicted by Hammett's σm values.
Reaction of α,β‐unsaturated acid chlorides with β‐diketones. Synthesis of 4,6,7,8‐tetrahydro‐2H‐1‐benzopyran‐2,5(3H)‐diones
Authors: Monroe Bruce M. 
Published: March 2009

AbstractReaction of an α,β‐unsaturated acid chloride with the anion of 5,5‐dimethyl‐1,3‐cyclohexane‐dione (2) gives either the enol ester (4) or a cyclized product (5), depending upon the reaction conditions. When the acid chloride is in excess, the ester is obtained. When the anion is in excess and the acid chloride is acryloyl or crotonyl, the cyclized product is obtained. A similar cyclized product (9) was formed from acryloyl chloride and an excess of the anion of 4‐hydroxy‐6‐methyl‐2‐pyrone (8).
The addition reaction of α‐azido ethers and α‐azido thioethers to phenylacetylene
Authors: Garcia‐Muñoz G. , Madroñero R. , Rico M. , Saldaña M. C. 
Published: March 2009

AbstractSeveral v‐triazoles were synthesized by 1,3‐dipolar cycloaddition of certain α‐azido ethers and α‐azidothioethers to phenylacetylene. In most of the cases the reaction led to the formation of the two isomeric v‐triazoles. Structural assignments for the products obtained were made on the basis of NMR data and chemical reactions. Characteristic differences between the NMR spectra of the isomers have been noted.
Benzimidazolinetriones. Reactions of 2,5,6‐ and 2,4,7‐benzimidazolinetriones
Authors: March Louis C. , Joullié Madeleine M. 
Published: March 2009

AbstractThe condensation of 2,5,6‐benzimidazolinetrione with ethylenediamine resulted in the formation of the 1,3‐dihydro‐2H‐imidazo[4,5‐g]quinoxalin‐2‐one ring system. The reaction of this trione with excess ethanethiol resulted in the isolation of three hydroquinones which were oxidized to the respective quinones. 2,4,7‐Benzimidazolinetrione was shown to undergo a Diels‐Alder reaction with isoprene and a mono‐addition reaction with benzenethiol.
Novel animation reactions of dihydrofurano[2,3‐d] pyrimidines
Authors: Campaigne E. , Ellis R. L. 
Published: March 2009

AbstractAlthough alkoxypyrimidines can be aminated to yield aminopyrimidines, monoamination of 2,4‐ or 4,6‐chloroalkoxypyrimidines results in chlorine displacement. Preferential alkoxy displacement in such systems is unusual. We now have evidence of such a displacement in the dihydrofurano[2,3‐d] pyrimidines (V). In some cases two types of products, formed by displacement of either the chlorine or alkoxy substituent, were obtained.
Reactions of 6‐hydrazino‐, 6‐hydroxylaminopurines and related derivatives
Authors: Giner‐Sorolla Alfredo 
Published: March 2009

Abstract7H‐Tetrazolo[5,1‐i]purine was prepared by nitrosation of 6‐hydrazinopurine and by reaction of 6‐chloropurine with sodium azide; it was converted to adenine upon catalytic hydrogenation. 6‐Hydroxylaminopurine was oxidized to 6‐nitrosopurine with manganese dioxide, while alkaline treatment of the former gave 6,6′‐azoxypurine. Nitrosation of 6‐hydroxylaminopurine afforded 6‐(N‐nitroso)hydroxylaminopurine. Reaction of 6‐chloropurine with 6‐hydrazinopurine led to 6,6′‐bisadenine; the corresponding ribosyl derivatives gave 6,6′‐bisadenosine. Upon air oxidation, 6,6′‐bisadenine was converted into 6,6′‐azopurine. The related 6‐thiosemicarbazino‐ and 6‐(N‐methyl)ureidopurine derivatives are also described. 6‐N‐(Nitroso)hydroxylaminopurine showed an inhibitory activity against several mouse tumors and leukemias.
The synthesis of certain ribofuranosylindazoles
Authors: Revankar Ganapathi R. , Townsend Leroy B. 
Published: March 2009

AbstractThe synthesis of 1‐(β‐D‐ribofuranosyl)indazole (4), 2‐(β‐D‐ribofuranosyl)indazole (5) and 6‐, 5‐, and 4‐nitro‐2‐(β‐D‐ribofuranosyl)indazole (8a, 8b, and 8c, respectively), has been accomplished in good yield by the condensation of the appropriate N‐trimethylsilylindazole (1, 6a, 6b, and 6c) with 2,3,5‐tri‐O‐acetyl‐D ‐ribofuranosyl bromide (2) followed by subsequent deacetylation of the reaction products. The site of ribosylation and the assignment of anomeric configuration for all nucleosides reported is discussed. This has furnished the first indazole nucleosides with assigned anomeric configurations and the site of ribosylation has been established on the basis of uv comparisons with model methyl compounds.
Studies in the chemistry of 1,2,5‐oxadiazole (II). Synthesis and properties of furazanodiazepines
Authors: Gasco A. , Ruá G. , Menziani E. , Nano G. M. , Tappi G. 
Published: March 2009

AbstractThis paper describes the synthesis and the properties of some furazanodiazepine derivatives obtained by condensing the appropriate β‐diketones with 3,4‐diaminofurazan. On the basis of U.V., I.R. and N.M.R. evidence a mono‐imino structure is suggested for the compounds obtained.Low temperature N.M.R. spectra suggest a rapid tautomensm for the dimethyl derivative.
Cleavage of NO bonds in 1,2,4‐oxadiazolines
Authors: Srimannarayana G. , Srivastava R. M. , Clapp Leallyn B. 
Published: March 2009

AbstractThe photochemical cleavage of the N‐O bond in 1,2,4‐oxadiazolines I to form acetamidines II was found to occur under mild conditions (ordinary light, 3560Å, or 2537Å). The weak N‐O bond in 3‐mcthyl‐4,5‐diphenyl‐1,2,4‐oxadiazoline (If) was also cleaved by catalytic reduction to give a molecular compound composed of benzyl alcohol and N‐phenylacetamidine, V.
The orientation in the ullmann‐fetvadjian acridine cyclizations with 2‐aminofluorene
Authors: Buu‐Hoï N. P. , Mangane M. , Jacquignon P. 
Published: March 2009

Abstract2‐Aminofluorene is shown to undergo the Ullmann‐Fetvadjian acridine cyclization with α‐naphthol and paraformaldehyde at position 3, to give the linear indenoacridine; a similar reaction performed with β‐naphthol afforded a mixture of the corresponding linear and angular indenoacridines.
Synthesis of some amino‐substituted furanopyrimidines and styrylpyrimidines
Authors: Campaigne E. , Ho J. , Bradford Mary 
Published: March 2009

Abstract5‐p‐Chlorophenyl‐6,6‐dimethyl‐5,6‐dihydro‐3H‐furano[2,3‐d]pyrimidine‐4‐one is readily converted to 4,6‐dichloro‐5‐β‐β‐dimethyl‐α‐ (p‐chlorostyryl)pyrimidine by warming in phosphorus oxychloride and acetic acid, behavior which is in strong contrast to that of the analogous 5‐phenyl derivative. The reaction provides a convenient source of 4‐amino‐6‐chloro‐5β,β‐dimethyl‐α‐ (p‐chlorostyryl)pyrimidines and 4,6‐diamino‐5‐β,β‐dimethyl‐α‐ (p‐chlorostyryl)pyrimidines, compounds of potential biological interest.
Trifluoromethylfurans II
Authors: Bambury R. E. , Miller L. F. 
Published: March 2009

AbstractEthyl acetoacetate reacted with 3‐bromo‐1,1,1‐trifluoro‐2‐propanone in the presence of base to give 3‐carbethoxy‐4,5‐dihydro‐4‐hydroxy‐2‐methyl‐4‐trifluoromethylfuran (I). Acid catalyzed dehydration of I gave the corresponding furan (III). Saponification of III gave 2‐methyl‐4‐trifluoromethyl‐3‐furoic acid which was decarboxylated to yield 2‐methyl‐4‐trifluoromethylfuran (V) for which a structure proof is presented. Conversion of the methyl groups of III and V to formyl groups is described.