Synthesis of uracils substituted in the position 5 or 5,6 with alkyl or cycloalkyl groups and their UV spectra

1979 ◽  
Vol 44 (8) ◽  
pp. 2426-2437 ◽  
Author(s):  
Ivan Bašnák ◽  
Jiří Farkaš
Keyword(s):  
Carbon Atom ◽  
Alkaline Medium ◽  
Cyclopropane Ring ◽  
Sodium Hydride ◽  
Chloroacetic Acid ◽  
Ethyl Formate ◽  
Uv Spectra ◽  
Lithium Diisopropylamide ◽  
Subsequent Reaction ◽  
Alkyl Derivatives

Lithium diisopropylamide used as a base in the Claisen condensation of alkylacetates and cycloalkylacetates with ethyl formate or acetate gave substantially higher yields of β-oxo esters than sodium hydride or sodium bis(trimethylsilyl)amide. Reaction of the obtained β-oxo esters with thiourea in an alkaline medium afforded 5- or 5,6-disubstituted 2-thiouracils Ib-XIIb which on subsequent reaction with chloroacetic acid were transformed into the uracil derivatives Ia-XIIa. The UV spectra of uracils substituted in the positions 5 or 6 with cyclopropane ring exhibit in the 265 nm region bathochromic shifts of 1 to 6.5 nm as compared with the correspondingly substituted alkyl derivatives. A qualitative correlation of these shifts with the electron deficit on the carbon atom bonded to the cyclopropane ring was attempted.

Macropolyhedral Boron-Containing Cluster Chemistry. A Metallathiaborane from S2B17H17: Isolation and Characterisation of [(PMe2Ph)2PtS2B16H16]; A neo-arachno Ten-Vertex Cluster Shape, and the Constitution of the [arachno-B10H15]- Anion

2005 ◽  
Vol 70 (4) ◽  
pp. 430-440 ◽  
Author(s):  
Michael J. Carr ◽  
Michael G. S. Londesborough ◽  
Jonathan Bould ◽  
Ivana Císařová ◽  
Bohumil Štíbr ◽  
...  
Keyword(s):  
Dft Calculations ◽  
Sodium Hydride ◽  
Hydrogen Atoms ◽  
Subsequent Reaction ◽  
Cluster Chemistry ◽  
Cluster Shape ◽  
Open Face

The deprotonation of S2B17H17 with sodium hydride and subsequent reaction with [PtCl2(PMe2Ph)2] gives the new macropolyhedral metallathiaborane [(PMe2Ph)2PtS2B16H16], of which the cluster consists of a conventional eleven-vertex nido {SB10} unit, fused, with two boron atoms in common, with a {PtSB8} unit of unique ten-vertex neo-arachno constitution and geometry. The latter geometry suggests a configuration for the previously structurally uncharacterised [B10H15]- anion; starting from this configuration, DFT calculations of structure and thence of boron nuclear shieldings, which are found very closely to mimic those found experimentally, thence support a fluxional structure for [B10H15]- with three {BHB(bridging)} and two {BH(endo)} hydrogen atoms around a six-membered open face.

Cyclization of 2-(2-bromoethoxy)-acetophenones and 5-(ω-haloalkoxy)-1,5-dihydro-2H-pyrrol-2-ones – Formation of five- to eight-membered oxygen-containing heterocycles via intramolecular alkylation

2004 ◽  
Vol 82 (5) ◽  
pp. 571-578 ◽  
Author(s):  
Kirill V Nikitin ◽  
Nonna P Andryukhova
Keyword(s):  
Sodium Hydride ◽  
Spiro Compounds ◽  
Lithium Diisopropylamide ◽  
Intramolecular Alkylation ◽  
High Yields

Under basic conditions (lithium diisopropylamide or sodium hydride in THF) 2-(2-bromoethoxy)-acetophenones were transformed to 3,4-dihydro[1]benzoxepin-5(2H)-ones (homochromanones) in high yields. The preparation of novel tetrahydropyrano[2,3-b]pyrrol-6(2H)-ones and 3,4-dihydro-2H-pyrrolo[2,1-b][1,3]oxazin-6(8aH)-ones and spiro compounds was performed using similar cyclization in moderate to good yields.Key words: cyclization, lithiation, spiro heterocycles.

scholarly journals Synthesis and crystal structures of two purpurin derivatives: 1,4-dihydroxy-2-propoxyanthraquinone and 2-butoxy-1,4-dihydroxyanthraquinone

2017 ◽  
Vol 73 (11) ◽  
pp. 1687-1691 ◽  
Author(s):  
Eric Bosch ◽  
Emily N. McClain
Keyword(s):  
Carbon Atom ◽  
Hydrogen Bonds ◽  
Sodium Hydride ◽  
Maximum Deviation ◽  
Independent Molecule ◽  
Asymmetric Unit ◽  
Terminal Carbon Atom ◽  
Butyl Group ◽  
Independent Molecules ◽  
Hydroxy Groups

The title compounds were obtained by deprotonation of 1,2,4-trihydroxyanthraquinone (purpurin) using sodium hydride followed by reaction with either 1-bromopropane or 1-bromobutane. 1,4-Dihydroxy-2-propoxyanthraquinone crystallizes as a 1:1 solvate from acetonitrile, C17H14O5·CH3CN. The anthraquinone core of the molecule is essentially planar and both hydroxy groups participate in intramolecular O—H...O (carbonyl) hydrogen bonds. The propyl chain is angled slightly above the plane of the anthraquinone moiety with a maximum deviation of 0.247 (2) Å above the plane for the terminal carbon atom. In contrast, 2-butoxy-1,4-dihydroxyanthraquinone, C18H16O5, crystallizes from nitromethane with two independent molecules in the asymmetric unit. The anthraquinone core of each independent molecule is essentially planar and both hydroxy groups on both molecules participate in intramolecular O—H...O(carbonyl) hydrogen bonds. The butyl chain in one molecule is also angled slightly above the plane of the anthraquinone moiety, with a maximum deviation of 0.833 (5) Å above the plane for the terminal carbon atom. In contrast, the butyl group on the second molecule is twisted out of the plane of the anthraquinone core with a torsion angle of 65.1 (3)°, resulting in a maximum deviation of 1.631 (5) Å above the plane for the terminal carbon atom.

Reactions of 3-butine-2-methyl-2-ol with isothiocyanates

1986 ◽  
Vol 51 (5) ◽  
pp. 1119-1126 ◽  
Author(s):  
Peter Kutschy ◽  
Milan Dzurilla ◽  
Ladislav Kniežo ◽  
Juraj Bernát ◽  
Ján Imrich ◽  
...  
Keyword(s):  
Carbon Atom ◽  
Sodium Hydride ◽  
Derivatives Of

3-Butine-2-methyl-2-ol reacts with isothiocyanates in the presence of sodium hydride in dimethylformamide to give various products depending on structure of the isothiocyanate residue. Isothiocyanates with the NCS group bound to sp2 carbon atom (phenyl, 4-bromophenyl, and styryl isothiocyanates) give the respective 1,3-oxazolidine derivatives. If the NCS group is bound to an sp3-hybridized carbon atom (ethyl and benzyl isothiocyanates), derivatives of 1,3-oxathiolane are formed. Acyl isothiocyanates (benzoyl and 3-phenylpropenoyl isothiocyanates) give products of substitution of the NCS group, viz. 1-butine-3-methyl-3-yl benzoate and 3-phenylpropenoic anhydride.

Facile Syntheses of Novel Acyclic Polycarboxylic Acids

2005 ◽  
Vol 60 (4) ◽  
pp. 408-412 ◽  
Author(s):  
Matthias Lutz ◽  
Jouni Pursiainen ◽  
Reijo Aksela
Keyword(s):  
Carboxylic Acids ◽  
Chloroacetic Acid ◽  
Reaction Step ◽  
Subsequent Reaction ◽  
Polycarboxylic Acids

The synthesis of novel di- and tricarboxylic acids is described. Starting from diethanolamine, a series of N-substituted diethanol derivatives were prepared which were converted in the subsequent reaction step into the corresponding carboxylic acids by treatment with chloroacetic acid. N,N-bis[2- (carboxymethoxy)ethyl]glycine was obtained by N-alkylation of glycine ethylester with ethyl 2-(2- bromoethoxy)acetate

Synthesis of Some 2'-C-Alkyl Derivatives of 9-(2-Phosphonomethoxyethyl)adenine and Related Compounds

1994 ◽  
Vol 59 (9) ◽  
pp. 2069-2094 ◽  
Author(s):  
Hana Dvořáková ◽  
Antonín Holý ◽  
Ivan Rosenberg
Keyword(s):  
Reaction Pathway ◽  
Sodium Hydride ◽  
Amino Group ◽  
Trimethylsilyl Derivative ◽  
Phosphonic Acids ◽  
Alkyl Derivatives ◽  
Hydrolysis Of ◽  
Trifluoromethyl Derivative ◽  
Derivatives Of ◽  
Related Compounds

To study the effect of β-substitution in 2'-alkyl derivatives of 9-(2-phosphonomethoxyethyl)adenine (Ia) on the antiviral activity or group specificity, these derivatives were synthesized. 9-(2-Hydroxyalkyl)adenines VIII were prepared by alkylation of adenine with suitably substituted oxiranes XIII or 2-hydroxyalkyl p-toluenesulfonates IV and VI. After protection of the adenine amino group by benzoylation (compounds IX) or amidine formation (compounds X), the intermediates were alkylated with diisopropyl p-toluenesulfonyloxymethanephosphonate (XI) in the presence of sodium hydride. After deprotection, the obtained phosphonate diesters XII were converted into phosphonic acids I by transsilylation and hydrolysis. This synthetic scheme was used for the preparation of ethyl (Ie), propyl (If), 2-propyl (Ig), 2-methylpropyl (Ih), cyclopropyl (Ii), cyclohexyl (Ij), benzyl (Ik) and phenyl (Il) derivatives. The 2'-trifluoromethyl derivative XXIIa was prepared analogously from 9-(2-hydroxy-3,3,3-trifluoropropyl)adenine (XXa), obtained by alkylation of adenine sodium salt with 2-hydroxy-3,3,3-trifluoropropyl bromide. 2'-Trimethylsilyl derivative XIXa was obtained by alkylation of adenine with 2-diisopropylphosphonomethoxy-3-(4-toluenesulfonyloxy)propyltrimethylsilane (XVII) followed by transsilylation and hydrolysis of diester XVIIIa. 2,6-Diaminopurine derivatives XVIIId and XXIIb were obtained analogously. 9-(3-Phosphonomethoxybutyl)adenine (XXVIII) and 9-(2-methyl-2-phosphonomethoxypropyl)adenine (XXXV) were prepared from the corresponding hydroxy derivatives XXVIb and XXXII, respectively, by the same reaction pathway as derivatives I.

Nucleophilic and acid-catalyzed cleavage of the cyclopropane rings of β,γ-unsaturated α-spirocyclopropyl ketones

1983 ◽  
Vol 61 (1) ◽  
pp. 78-85 ◽  
Author(s):  
Peter Yates ◽  
Patrick Hugh Helferty ◽  
Paul Mahler
Keyword(s):  
Nucleophilic Addition ◽  
Cyclopropane Ring ◽  
Sodium Hydride ◽  
Ring Cleavage ◽  
Similar Treatment ◽  
Torsional Strain ◽  
Rate Of Reaction ◽  
Saturated Compound ◽  
Acid Catalyzed ◽  
Rapid Protonation

Treatment of isophorone (8) with sodium amide and 1,2-dibromomethane gives 6,6-dimethyl-8-methylenespiro[2.5]octan-4-one (9) and 6,6,8-trimethylspiro[2.5]oct-7-en-4-one (10); similar treatment of 3-methylcyclohex-2-en-1-one (5) gives analogous spiro compounds 6 and 7 together with 8-methylenedispiro[2.1.2.3]decan-4-one (11) and 8-methyldispiro[2.1.2.3]dec-8-en-4-one (12). The spiro ketones 6, 7, 9, and 10 undergo homoconjugate nucleophilic addition on being heated in morpholine with cleavage of the cyclopropane rings to give 2-[2-(4-morpholinyl)ethyl]cyclohex-2-en-1-ones. The rates of reaction are much greater for the exo methylene compounds 6 and 9 than for their endo isomers 7 and 10, but the rate of reaction of 10 is only slightly greater than that of the corresponding saturated compound, 6,6,8-trimethylspiro[2.5]octan-4-one (15). A corresponding rate differential between 9 and 10 is observed in their reactions with isophorone (8) and sodium hydride to give 2,2′-(ethanediyl)bis[3,5,5-trimethylcyclohex-2-en-1-one] (18). The acceleration in the cases of 6 and 9 relative to that of 15 is attributed to spiroactivation by both the carbonyl and exocyclic ethylenic groups; the much smaller effect of the endocyclic ethylenic groups in the cases of 7 and 10 is ascribed to torsional strain in the transition states for ring opening. The spiro ketones 6, 7, 9, and 10 also undergo acid-catalyzed cyclopropane ring cleavage in ethanol, giving 2-(2-ethoxyethyl)cyclohex-2-en-1-ones. Again the exo methylene compounds 6 and 9 react much more rapidly than their endo isomers 7 and 10; this is considered to be due to factors analogous to those operative in the nucleophilic addition reactions and/or the more rapid protonation of the exo methylene compounds.

Synthesis of 5-Phenyl-2(1H)-pyrimidinone Nucleosides

1996 ◽  
Vol 61 (3) ◽  
pp. 458-477 ◽  
Author(s):  
Marcela Krečmerová ◽  
Hubert Hřebabecký ◽  
Milena Masojídková ◽  
Antonín Holý
Keyword(s):  
Thionyl Chloride ◽  
Chloroacetic Acid ◽  
Equilibrium Mixture ◽  
Side Product ◽  
Subsequent Reaction ◽  
Silyl Derivative ◽  
Tetrabutylammonium Fluoride ◽  
Trimethylsilyl Trifluoromethanesulfonate ◽  
Methanolic Ammonia ◽  
Tin Tetrachloride

Reaction of 2-phenyltrimethinium salt 1 with thiourea and subsequent reaction with chloroacetic acid afforded 5-phenyl-2(1H)-pyrimidinone (3). Its silyl derivative 4 was condensed with 1-O-acetyl-2,3,5-tri-O-benzoyl-D-ribofuranose under catalysis with tin tetrachloride or trimethylsilyl trifluoromethanesulfonate to give protected nucleoside 5 together with 5',O6-cyclo-5-phenyl-1,3-bis- (β-D-ribofuranosyl)-6-hydroxy-5,6-dihydro-2(1H,3H)-pyrimidinone (7). The greatest amounts of 7 were formed with the latter catalyst. Nucleosidation of the silyl derivative 4 with protected methyl 2-deoxy-D-ribofuranoside 8 or 2-deoxy-D-ribofuranosyl chloride 9 afforded 1-(2-deoxy-3,5-di-O-p-toluoyl-β-D-ribofuranosyl)-5-phenyl-2(1H)-pyrimidinone (10) and its α-anomer 11. Reaction of 10 and 11 with methanolic ammonia gave free 2'-deoxynucleosides 12 and 13. Compound 13 was converted into 5'-O-tert-butyldiphenylsilyl-3'-O-mesyl derivative 14 which on heating with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and subsequent cleavage with tetrabutylammonium fluoride afforded 2',3'-dideoxy-2',3'-didehydronucleoside 15. Reaction of the silyl derivative 4 with 1,2-di-O-acetyl-3,5-di-O-benzoylxylofuranose (18), catalyzed with tin tetrachloride, furnished 1-(2-O-acetyl-3,5-di-O-benzoyl-β-D-xylofuranosyl)-2(1H)-pyrimidinone (19) which was deprotected to give the β-D-xylofuranosyl derivative 22. As a side product, the nucleosidation afforded the β-D-xylopyranosyl derivative 23. Deacetylation of compound 19 gave 1-(3,5-di-O-benzoyl-β-D-xylofuranosyl)-5-phenyl-2(1H)-pyrimidinone (24) which on reaction with thionyl chloride afforded 2'-chloro-2'-deoxynucleoside 25 and 2',O6-cyclonucleoside 26. Heating of compound 25 with DBU in dimethylformamide furnished the lyxo-epoxide 27 which on reaction with methanolic ammonia was converted into free 1-(2,3-anhydro-β-D-lyxofuranosyl)-5-phenyl-2(1H)-pyrimidinone (28). Reaction of 1,2-di-O-acetyl-5-O-benzoyl-3-O-methanesulfonyl-D-xylofuranose (30) with silyl derivative 4 gave the nucleoside 31 which by treatment with DBU was converted into an equilibrium mixture of 5'-benzoylated arabinofuranoside 33a and its 2',6-anhydro derivative 33b.

The Synthesis of 4-Hydroxydithiocoumarins: A Case of Unusual Tautomer Stability

1987 ◽  
Vol 40 (7) ◽  
pp. 1179 ◽  
Author(s):  
JE Andersonmckay ◽  
AJ Liepa
Keyword(s):  
Carbon Disulfide ◽  
Sodium Hydride ◽  
Strong Acid ◽  
Sodium Perborate ◽  
Alkyl Derivatives ◽  
Acid Anhydrides

2'-Chloroacetophenones react with carbon disulfide in the presence of sodium hydride to form 4-hydroxydithiocoumarin anions. Kinetic protonation provides the 4-hydroxydithiocoumarins which can be tautomerized to 2-mercapto-1-thiochromones by treatment with strong acid. � Both tautomers are quite stable and do not readily interconvert. Alkylation of either 4-hydroxydithiocoumarin or 2-mercapto-1-thiochromone provides S-alkyl derivatives exclusively while acylation with acid anhydrides gives mixtures of O- and S-acyl products. Oxidation with sodium perborate yields the exocyclic monosulfoxide while m-chloroperbenzoic acid gives the exocyclic sulfone.

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