bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quinoxalinediones. I. Synthesis of 6‐methyl‐5,8‐quinoxalinediones
Authors: Levy Michèle R. W. , Joullié Madeleine M. 
Published: March 2009

AbstractVarious synthetic routes were investigated as potential methods of preparation of 6‐methyl‐5, 8‐quinoxalinediones which could be useful as antimetabolites of vitamin K. The preparation of 2,3‐dimethyl‐5,8‐quinoxalinedione (II) was achieved by the condensation of 2,3‐diamino‐1,4‐dimethoxybenzene with diacetyl. Demethylation was accomplished by the use of aluminum chloride in benzene and the resulting hydroquinone (I) was oxidized with dry silver oxide to the quinone (II). An analogous synthetic route could not be used to prepare 2, 3, 6‐trimethyl‐5, 8‐quinoxalinedione (VII). 6‐Methyl‐5, 8‐quinoxalinediones were prepared from 2,3‐dinitro‐4‐methoxy‐6‐methylacetanilide (III) which was reduced and condensed with appropriate carbonyl compounds. Acid hydrolysis yielded aminophenols which were oxidized to (VII) and (VIII) with chromic acid. The ultraviolet and infrared spectra of the compounds prepared are recorded.
Hydrazinopyrimidines
Authors: Wiley Richard H. , Lanet Jean , Hussung K. H. 
Published: March 2009

AbstractA variety of hydrazino and dihydrazino‐5‐nitropyrimidines and their derivatives have been prepared by displacement reactions or reaction sequences from 2,4‐ or 4,6‐dichloro‐5‐nitropyrimidine. These include 2,4‐ and 4, 6‐dihydrazino, 2‐dimethylamino‐4‐hydrazino, 2‐hydrazino‐4‐dimethylamino, 2‐morpholino‐4‐hydrazino, and 2‐hydrazino‐4‐amino‐5‐nitropyrimidines. 2,4‐Dihydrazino‐5‐nitropyrimidine on condensation with selected aldehydes yielded a series of dihydrazones. Of these, p‐methoxybenzaldehyde (5‐nitropyrimidyl‐2, 4‐dihydrazone) showed a reproducible but slight activity in Sarcoma‐180 tests.
Diazepines. I. 3,8‐Dihalo‐11H‐dibenzo[c,f]‐[1,2] diazepines
Authors: Catala Adria , Popp Frank D. 
Published: March 2009

AbstractThe title compounds were prepared by lithium aluminum hydride reduction of the corresponding 2, 2′‐dinitro‐4, 4′‐dihalodiphenylmethanes. Peracetic acid oxidation of the title compounds led to the N‐oxides, chromic anhydride oxidation led to an 11‐ keto compound, and hydrazine ‐ Raney nickel reduction led to the dihydro compounds.
Imidazo[4,5‐d]pyridazines. III. The Synthesis of 2‐phenylimidazo [4,5‐d]‐pyridazines
Authors: Malm Miriam , Castle Raymond N. 
Published: March 2009

AbstractBased upon an analogy with “Dyrenium”, (6‐phenyl‐2,4,7‐triaminopteridine) (I), 4,7‐diamino‐2‐phenylimidazo[4, 5‐d]pyridazine (II) has been prepared. This compound has been found to possess diuretic activity. In addition a number of other substituted 2‐phenylimidazo[4, 5‐d]pyridazines have been prepared.
The influence of alkyl substituents on the rates of hydrolysis of 2‐imidazolines
Authors: Harnsberger B. G. , Riebsomer J. L. 
Published: March 2009

AbstractA number of 2‐imidazolines have been hydrolyzed in basic 95% ethanol, and the activation energies and half‐lives of these reactions have been determined. The reactions are base catalyzed and lead to the formation of amides through fission of the ring between positions one and two. The reaction rates are strongly influenced by various ring substituents.
The chemistry of pyrazine and its derivatives. X. The mono‐ and diacylation of tetramethylpyrazine
Authors: Chakrabartty Sujit K. , Levine Robert 
Published: March 2009

AbstractBy the use of sodium amide in liquid ammonia or phenyllithium in ether as the condensing agent it has been possible to synthesize a series of ketones containing the pyrazine ring with the structure, RCOCH2C4N2(CH3)3 where R is alkyl, aryl or heterocyclic. Also, under appropriate conditions, tetramethylpyrazine has been diacylated to give three diketones of the type (2‐RCOCH2)‐(6‐R' COCH2)C4N2(CH3)2‐3, 5.
The kinetics of the hydrolysis of some 2‐imidazolines
Authors: Harnsberger B. G. , Riebsomer J. L. 
Published: March 2009

AbstractA 1,2‐disubstituted‐2‐imidazoline was hydrolyzed in aqueous solutions of varying PH. The rate of reaction approaches a maximum as the base concentration is increased. Salt effects and activation energies also seem to vary with PH.
Difluorodiazirine. II. Difluoromethane derivatives
Authors: Mitsch Ronald A. 
Published: March 2009

AbstractThe photolysis of difluorodiazirine is a convenient technique for the formation of difluorocarbene. Difluorocarbene, generated in this manner, has been shown to react with chlorine, iodine, dinitrogen tetroxide and nitryl chloride to yield the corresponding difluoromethane derivatives.
3‐Substituted thiophenes. XII. Bromination of β‐3‐thienylacrylic acid
Authors: Campaigne E. , Fedor L. , Johnson Roger E. 
Published: March 2009

AbstractBromination of β‐3‐thienylacrylic acid in glacial acetic acid gave β‐(2‐bromo‐3‐thienyl)‐acrylic acid with an equivalent of bromine, and β‐(2,5‐dibromo‐3‐thienyl)‐α,β‐dibromo‐propionic acid with excess bromine. In hot carbon tetrachloride, an excellent yield of the stable olefinic addition product, β‐3‐thienyl‐α,β‐dibromopropionic acid, was obtained, and its structure was confirmed by conversion to β‐bromo‐3‐thienylethylene in base. 3‐Thenaldehyde underwent a Darzen's Glycidic Ester condensation to produce ethyl β‐3‐thienyl‐α,β‐epoxypropionate, but treatment of this ester or the salt of its derived acid with hydrogen bromide led to the formation of unstable products. The structure of the bromo‐acids and derivatives were confirmed by unequivocal syntheses and/or by nuclear magnetic resonance spectra.
Analogs of tetrahydrofolic acid. XIX. On the mode of binding of the pyrimidyl moiety of n‐(2‐amino‐4‐hydroxy‐6‐methyl‐5‐pyrimidylpropionyl)‐P‐aminobenzoyl‐l‐glutamic acid to 5,10‐methylenetetrahydrofolate dehydrogenase
Authors: Baker B. R. , Almaula Prabodh I. 
Published: March 2009

AbstractThe synthesis of several analogs of the title compound (Ia) which had (a) replacement of the 4‐hydroxy group by thiol, (XXVIIIa), (b) replacement of the 6‐methyl group by 6‐phenyl (Ib), (c) replacement of the 2‐amino group by 2‐thiol (XXVI), or (d) replacement of both the 4‐hydroxyl and 6‐methyl groups by 4‐thiol and 6‐phenyl, respectively, have been described. The key intermediate was the appropriate 2,4,6‐trisubstituted5‐pyrimidyl‐propionic acids which were synthesized by suitable transformation of the 5‐pyrimidyl‐propionitriles (VIII and XII). Replacement (a) or (b) gave an improvement in inhibition of 5, 10 ‐ methylenetetrahydrofolate dehydrogenase, but the two changes in the same molecule (d) did not further increase inhibition. The 2‐amino group of the title compound (Ia) can be replaced by 2‐thiol without decreasing the inhibitory properties of Ia.
Amino Acids. I. DL‐β‐(diazaphenyl)alanines
Authors: Haggerty William J. , Springer Robert H. , Cheng C. C. 
Published: March 2009

AbstractWith the publication of this work, all six theoretically possible isomers of DL‐diaza‐phenylalanines have now been reported. 2‐Pyrazinyl‐ (VII), 3‐pyridazinyl‐ (VIII), 4‐pyridazinyl‐ (IX), 4‐pyrimidinyl‐ (X), and 2‐pyrimidinylalanine (XI) were synthesized by the catalytic (in the cases of VII‐X) or stannous chloride (in the case of XI) reduction of the corresponding (α‐oximino‐β‐(diazaphenyl)propionic acids. These compounds were in turn prepared by the Claisen condensation of appropriate methyldiazines with diethyl oxalate followed by treatment of the resulting pyruvic ester with hydroxylamine.Condensation of 5‐bromomethylpyrimidine with diethyl N‐ carbobenzoxyaminomalonate yielded diethyl N‐carbobenzoxyarmno‐(5‐pyrimidinylmethyl)malonate. Hydrolysis and debenzylation of the condensation product readily gave the desired 5‐pyrhidinylalanine (XII).
Neighboring Group participation by the tetrahydrofuran ring
Authors: Kwiatkowski George T. , Kavarnos Spiro J. , Closson W. D. 
Published: March 2009

AbstractNeighboring group participation in the solvolytic reactions of a series of ω‐(2‐tetx‐a‐hydrofuran)alkyl p ‐ bromobenzenesulfonate esters has been investigated. Anchimeric assistance to solvolysis is most pronounced in the case of 3‐(2‐tetrahydrofuran)propyl p‐bromobenzenesulfonate where a 1‐oxabicyclo[3.3.0]octane cation can form. A “special salt effect” and an “induced common ion effect” were observed in the acetolysis of this ester. It appears that the tetrahydrofuran ring is about twice as effective as the methoxyl group in neighboring group participation.
Analogs of tetrahydrofolic acid. XXI. Synthesis of 6‐bromomethyl‐5‐(p‐chlorophenyl)‐2,4‐diaminopyrimidine and its evaluation as a dihydrofolic reductase inhibitor
Authors: Baker B. R. , Jordaan Johannes H. 
Published: March 2009

AbstractThe title compound (IV) has been synthesized from p‐chlorophenylacetonitrile by Claisen condensation with ethyl ethoxyacetate, conversion to an enol ether, then reaction with guanidine to give the key intermediate 5‐(p‐chlorophenyl)‐2,4‐diamino‐6‐ethoxymethyl‐pyrimidine (V). Cleavage of the ethyl ether of V with hydrogen bromide in acetic acid gave IV. The bromomethylpyrimidine (IV) was a good reversible inhibitor of dihydrofolic reductase from pigeon liver, but IV was not an irreversible inhibitor of the enzyme.
Polyfunctional aliphatic compounds VI. The cyclization of dinitriles to benzazepines
Authors: Johnson Francis , Nasutavicus W. A. 
Published: March 2009

AbstractThe action of hydrogen bromide or iodide on aryl‐o‐diacetonitriles has been studied and found to give condensed azepine derivatives. This constitutes a new and interesting synthesis of seven‐membered ring nitrogen heterocycles. The structure of the parent substance has been shown by physical and chemical means to be 2‐amino‐4‐halo‐1H‐3‐benzazepine. Several related compounds have been prepared and assigned similar structures by analogy. A number of reactions of 2‐amino‐4‐bromo‐1H‐3‐benzazepine (III) have been examined. It is concluded that the reactivity of the bromo group is similar to that of 2‐bromopyridine. In its reactions, 2‐amino‐1H‐3‐benzazepine not only has some of the character of 2‐aminopyridine but resembles the simple amidines also.
The chemistry of heterocycles. III. 2H‐1,3‐benzoxazine‐2,4(3H)‐dione and Some 3‐substituted derivatives.
Authors: Crum J. D. , Franks J. A. 
Published: March 2009

AbstractThe preparation of 2H‐1,3‐benzoxazine‐2,4(3H)‐dione, the sodium salt, and the p‐anisoyl, benzoyl, m‐bromobenzoyl, benzyl, trans‐cinnamoyl, ethyl, myristoyl, p ‐nitro‐benzyl, phenyl and p‐phenylphenacyl derivatives substituted on 2H‐1,3‐benzoxazine‐2,4‐(3H)‐dione (I) at position 3 together with their infrared and ultraviolet spectra are described.
A synthesis of 7‐substituted benzo[b]thiophene derivatives
Authors: Macdowell D. W. H. , Greenwood Thomas D. 
Published: March 2009

AbstractIn order to develop a method for synthesizing 7‐substituted derivatives of benzo[b]‐thiophene, the benzo[b]thiophene analog of 1‐tetralone, 7‐oxo‐4, 5, 6, 7‐tetrahydrobenzo‐[b]thiophene has been synthesized using as starting material the readily accessible 3‐bromothiophene. The structure of this ketone has been verified by elemental analysis, spectra and conversion to derivatives of benzo[b]thiophene of known structure. Several hitherto unreported 7‐substituted derivatives of benzo[b]thiophene have been prepared from the cyclic ketone.
Analogs of tetrahydrofolic acid. XXIII. 1‐(ω‐phenylalkyl)‐4,6‐diamino‐1,2‐dihydro‐s‐triazines as inhibitors of dihydrofolic reductase
Authors: Baker B. R. , Ho Beng‐Thong 
Published: March 2009

AbstractA series of 1‐(ω‐phenylalkyl)‐4,6‐diamino‐1, 2‐dihydro‐s‐triazines was synthesized by acid catalyzed condensation of 1‐(ω‐phenylalkyl)biguanides with acetone, aromatic aldehydes and ω‐phenylalkyl aldehydes; the intermediate biguanides were prepared by fusion of ω‐phenylalkylamines with cyanoguanidine at 150°. 4, 6‐Diamino‐1, 2‐dihydro‐2,2‐dimethyl‐1‐(4‐phenylbutyl)‐ and 1‐(3‐phenylpropyl)‐s‐triazines (Xe and Xd) were potent inhibitors of dihydrofolic reductase, being complexed with the enzyme about two hundred times better than the substrate, dihydrofolic acid; further Xd and Xe were about 15‐fold better inhibitors of dihydrofolic reductase than the earlier investigated 1‐(p‐chlorophenyl)‐4, 6‐diamino‐1,2‐dihydro‐2,2‐dimethyl‐s‐triazine, the antimalarial drug.When the 2,2‐dimethyl group was replaced by p‐acetamidophenyl (IX) or phenyl (VIII), in inhibitors such as Xd and Xe, activity was reduced only 5‐30 fold; the corresponding change in 1‐(m‐chlorophenyl)‐4, 6‐diamino‐1,2‐dihydro‐2, 2‐dimethyl‐s‐triazine (V) gave a 19,000‐fold reduction in activity with the 2‐(p‐acetamidophenyl) analog (VII) and a 550‐fold decrease in activity with the 2‐phenyl analog. These decreases in activity are attributed to a combination of intramolecular steric effects, intermolecular (enzymeinhibitor) steric inhibition of binding, and inductive effects. By evaluation of suitable candidate compounds, these effects were partially separated for individual study.
Steroids. XIX. 3‐phenyl ‐ and 3‐ethyl‐4‐azacholestanes
Authors: Doorenbos Norman J. , Kerridge Kenneth A. 
Published: March 2009

AbstractThe hydrogenation of 4‐methyl‐4‐aza‐5‐cholesten‐3‐one (III) to yield the 5α‐ and 5β‐isomers under acid conditions is described. The reaction of III and 4‐methyl‐4‐aza‐5α‐cholestan‐3 ‐ one with phenylmagnesium bromide, ethylmagnesium iodide, phenyllithium and ethyllithium to yield 3‐substitutcd steroids is reported. Hydrogenation of these 3‐substituted steroids yielded 4‐methyl‐3ξ‐phenyl‐4‐aza‐5α‐cholestane and 3ξ‐ethyl‐4‐methyl‐4‐aza‐5α‐cholestane (XIII). XIII inhibits the biosynthesis of cholesterol.
An investigation of abnormal products in the reaction of benzyl and 2‐thenyl grignard reagents with 14C‐carbon dioxide
Authors: Campaigne E. , Collins Clair J. 
Published: March 2009

AbstractAn investigation of the abnormal products formed in the carbonation of benzyl and 2‐thenyl Grignard reagents has been carried out. Using the reverse isotope dilution technique, it has been shown that neither ortho‐ nor para‐toluic acids are formed in measurable amounts during the reaction of benzylmagnesium bromide with carbon dioxide. 2‐Thenylmagnesium chloride reacts to produce acids, about 64% of which is the normal product, 2‐thienylacetic acid, 30% the ortho ‐abnormal product, 2‐methyl‐3‐thenoic acid, and probably a small amount (1.0 – 1.5%) is the Para ‐abnormal product, 5‐methyl‐2‐thenoic acid.
Die kristall‐ und molekülstrutur des 1,4,6,9‐tetrachlorphenazins
Authors: Riganti Vincenzo , Locchi Stelio , Curti Renato , Bovio Bruna 
Published: March 2009

AbstractDie Kristall‐ und Molekülstruktur des 1,4,6,9‐Tetrachlorphenazins C12H4N2Cl4 wurde röntgenographisch bestimmt. Die Kristalleo sind monoklin, Raumgruppe P21/n, und ergeben folgende Gitterkonstanten: a = 3.95 Å, b = 14.06 Å, c = 10.80 Å, β = 94°37′. Die intermolekularen Abstände stimmen mit denjenigen aus den van der Waals'schen Radien überein, mit Ausnahme eines C1….C1 Abstandes, der ein wenig kürzer als erwartet ist. Der intramolekdare CC1‐Abstand beträgt: 1.718 Å.
Mass spectrometry of benzo[a]‐ and benzo[c]acridines
Authors: Buu‐Hoi N. P. , Orley C. , Mangane M. , Jacquignon P. 
Published: March 2009

AbstractThe mass spectrograms of fourteen benzo[a]‐ and benzo[c]acridines, several of which are carcinogens, have been determined, and the following main features emerge: (a) presence of strong peaks corresponding to several stages of dehydrogenation; (b) very little fragmentation of the polycyclic frame, with, in ethylbenzacridines, a noteworthy splitting of methyl groups; and (c) importance of the double‐charged ions, some of which contribute more to the ionic current than do the corresponding single‐charged ones. The pattern of the spectrograms can vary considerably with the position of the substituents.
Morphanthridines II. 11‐aminoalkyl‐5,6‐dihydromorphanthridines
Authors: Drukker Alexander E. , Judd Claude I. , Spoerl Joan M. , Kaminski Frank E. 
Published: March 2009

AbstractButyl lithium converts 5‐substituted‐5,6‐dihydromorphanthridines to the 11‐position anion. Treatment of this lithium anion with aminoalkyl halides affords the 11‐aminoalkylated derivatives. Catalytic hydrogenation causes reductive cleavage of benzylamino bridge of the morphanthridine ring, a reaction which is used to structurally relate these compounds to the known 11‐aminoalkylidene‐5, 6‐dihydromorphanthridines
The synthesis of 5‐fluoro‐ and 7‐methyl‐indole and ‐tryptophane
Authors: Hoffmann Eliahu , Ikan Raphael , Galun Arjeh B. 
Published: March 2009

Abstract5‐Fluoroindole was prepared in 4 steps in 46% overall yield from m‐fluorotoluene. 7‐Methylindole was prepared in 2 steps 2 from 6‐dimethylaniline. Both compounds were transformed to the corresponding tryptophanes in high yields. The final hydrolytic step was carried out in aqueous acidic medium.
Analogs of tetrahydrofolic acid. XXIX. Hydrophobic bonding to dihydrofolic reductase. II. On the mode of phenyl binding of 1‐aryl‐4,6‐diamino‐1,2‐dihydro‐2,2‐dimethyl‐s‐triazines
Authors: Baker B. R. , Ho Beng‐Thong 
Published: March 2009

AbstractThe inhibition of dihydrofolic reductase by twenty appropriately 1‐substituted‐4, 6‐diamino‐1, 2 ‐ dihydro‐2, 2‐dimethyl‐s‐triazines were compared in order to shed light on the mode of phenyl binding of 1‐aryl‐1,2‐dihydro‐s‐triazines. When the 1‐phenyl group was substituted by a cationic group at the 4‐position or an anionic group at either the 3‐ or 4‐position, a large loss in affinity by the enzyme for the resultant inhibitor was noted. This loss in affinity is best explained by the concept that the 1‐aryl group complexes with a hydrophobic region on the enzyme and that the hydrophobic region repels any aryl group bearing either a positively or negatively charged group. p‐Substituents coplanar with the 1‐aryl group caused a steric interaction with the enzyme resulting in considerable loss in binding to this enzyme isolated from pigeon liver; this steric effect was considerably less in the m‐position. Inductive effects of 1‐phenyl substituents on a possible charge‐transfer complex of the 1‐aryl group or on the binding ability of the 4,6‐diamino‐1,2‐dihydro‐s‐triazine ring system could not be correlated with the Hammett sigma‐values; therefore these effects were considered to be of minor importance.
Analogs of tetrahydrofolic acid. XXX. Inhibition of dihydrofolic reductase by some 6‐substituted 2,4‐diamino‐s‐triazines
Authors: Baker B. R. , Ho Beng‐Thong 
Published: March 2009

AbstractFour different routes to 6‐alkyl‐, 6‐aryl‐, and 6‐aralkyl‐2,4‐diamino‐s‐triazines were investigated. The most convenient was reaction of an ester with biguanide in methanol at room temperature. Seven of these 6‐substituted 2,4‐diamino‐s‐triazines were investigated as inhibitors of dihydrofolic reductase. As a class they were weaker inhibitors than the corresponding 2,4‐diamino‐6‐substituted pyrimidines, this difference being attributed to the weaker basicity of the former class. Although hydrophobic bonding by 6‐alkyl and 6‐aralkyl groups on 2 the 4‐diamino‐s‐triazine system could be detected, the extent of hydrophobic bonding was much weaker than that previously seen with 2,4‐diaminopyrimidine containing a 5‐alkyl or 5‐aralkyl group or 1‐alkyl‐ and 1‐aralkyl‐2,4‐diamino‐1,2‐dihydro‐2,2‐dimethyl‐s‐triazines.
Dehydration of 4‐oximinocarboxylic acids with dicyclohexylcarbodiimide
Authors: Masaki M. , Matsukubo H. , Masuzawa K. , Chigira Y. , Ohta M. 
Published: March 2009

AbstractTreatment of 4‐oximino‐4‐phenylbutyric acid with dicyclohexylcarbodiimide gave 6H‐3‐phenyl‐4, 5‐dihydro‐6‐oxo‐1, 2‐oxazine (IId), which was characterized by its infrared spectrum and some reactions. Ring cleavage of IId was easily accomplished by acid or base such as hydrochloric acid, alcohol or amines. The treatment of 4‐oximino‐valeric acid with dicyclohexylcarbodiimide was also studied.
Studies of heteroaromatic systems by nuclear magnetic resonance spectroscopy. 4‐pyrimidones and 4‐pyrimidthiones
Authors: Bauer Ludwig , Wright George E. , Mikrut Bernard A. , Bell Charles L. 
Published: March 2009

AbstractProton magnetic resonance spectral parameters of 4‐pyrimidone, 1‐ and 3‐alkyl‐4‐pyrimidones as well as some of their thione analogs are presented and are compared to those of 4‐substituted pyrimidines. It was found that the ortho, meta and para coupling constants in each series were constant for 4‐substituted pyrimidines, the 1‐alkyl‐ and the 3‐alkyl‐4‐pyrimidones. A particularly large meta (J2, 6) coupling constant was an outstanding feature found in 1‐methyl‐, 1‐ethyl‐ and 1‐benzyl‐4‐pyrimidones and also in 1‐methyl‐4‐pyrimidthione but was virtually zero for the corresponding 3‐alkyl‐4‐pyrimidones. These findings are interpreted in terms of the aromatic character of these 4‐pyrimidones and thiones. During the synthetic aspects of this work, an interesting carbon‐sulfur cleavage was discovered when it was observed that 2‐benzylmercapto‐4‐pyrimidones were readily hydrolyzed by hot concentrated hydrochloric acid to the corresponding 2‐thiouracils.
Fused‐ring systems containing 1,2,4‐benzo thiadiazines. II. Reactions of o‐amino‐n‐hydroxybenzenesulfonamides
Authors: Wei Peter H. L. , Bell Stanley C. , Childress Scott J. 
Published: March 2009

Abstracto‐Amino‐N‐hydroxybenzenesulfonamides have been treated with aldehydes to prepare 2‐hydroxy‐1,2,4‐benzothiadiazine 1,1‐dioxides. These products have permitted the fusion of an additional ring to the “b” face of the benzothiadiazine. Analogs of the tricyclic compounds have been made in other ways.
Pyrimidines. XVII. I‐(Tetrahydro‐2‐pyranyl)cytosine, ‐uracil, ‐thymine and related compounds
Authors: Noell C. Wayne , Cheng C. C. 
Published: March 2009

AbstractIn view of the reported biological activities of antibiotics Amicetin and Blasticidin S, 1‐(tetrahydro‐2‐pyranyl)cytosine, ‐uracil, ‐thymine and related compounds were synthesized. These compounds were prepared by the Hilbert‐Johnson method from 2‐chloro‐tetrahydropyran and corresponding 2,4‐dimethoxypyrimidines.
Preparation and some reactions of 3,9‐dichloro‐2,4,8,10‐tetraoxa‐3,9‐diphosphaspiro[5.5] undecane‐3,9‐disulfide
Authors: Rätz Rudi , Bliss Arthur D. 
Published: March 2009

Abstract3, 9‐Dichloro‐2, 4, 8, 10‐tetraoxa‐3, 9‐diphosphaspiro[5. 5]undecane‐3,9‐disulfide (I), has been synthesized by treating a dimethylacetamide solution of 2, 4, 8, 10‐tetraoxa‐3,9‐diphosphaspiro[5. 5]undecane‐3, 9‐disulfide (III) with carbon tetrachloride. A number of other known methods for converting dialkyl phosphorothioites to thiophosphorochloridates were also applied to III, but all failed to produce I. Chlorination of either I or III gave an acyclic product, 4, 4‐bis(chloromethyl)‐1, 1, 7, 7‐tetrachloro‐2, 6‐dioxa‐1, 7‐di‐phosphaheptane‐1, 7‐dioxide (IV), in nearly quantitative yield. The same compound was also obtained by the previously known method of chlorinating 3, 9‐dichloro‐2,4,8,10‐tetraoxa‐3, 9‐diphosphaspiro[5.5]undecane (II). The treatment of pentaerythritol with phosphorus pentachloride gave IV in minor amount along with a 25% yield of 4,4‐bis‐(chloromethyl)‐1‐chloro‐2, 6‐dioxa‐1‐phosphacyclohexane‐1‐oxide (VII). The hydrolysis of I in heated aqueous sodium carbonate gave, after acidification, 3,9‐dihydroxy‐2,4,8,10‐tetraoxa‐3, 9‐diphosphaspiro[5. 5]undecane‐3, 9‐disulfide (VIII). A number of derivatives were prepared by reaction of I with phenoxides and amines. The corresponding thio‐phosphorofluoridate XI was prepared by treatment of I with potassium fluoride in dioxane.