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.

The synthesis of meso-Hexoestrol[3,4-D2] and some related specifically deuterated compounds

1974 ◽  
Vol 27 (8) ◽  
pp. 1743 ◽  
Author(s):  
DJ Collins ◽  
JJ Hobbs
Keyword(s):  
Methyl Ketone ◽  
Sodium Hydride ◽  
Dimethyl Sulphoxide ◽  
Reduction Sequence ◽  
Hydride Reduction ◽  
Lithium Aluminium ◽  
Methylmagnesium Iodide ◽  
High Yields ◽  
Unsaturated Nitrile ◽  
Hofmann Elimination

Condensation of p-methoxyphenylacetonitrile with p-methoxypropiophenone in the presence of sodium hydride in dimethyl sulphoxide at 65� gave (Z)-(23%) and (E)-2,3-bis(p-methoxyphenyl)pent-2-enenitrile(16%). The reduction of this α,β-unsaturated nitrile with lithium aluminium deuteride in tetrahydrofuran, and workup with D2O or with H2O, gave high yields of erythro-2,3-bis(p-methoxy-phenyl)valeronitrile[2,3-D2], or -[3-D], respectively. Conversion of the dideuteronitrile into the corresponding methyl ketone with methylmagnesium iodide, followed by a hydride reduction-tosylation-hydride reduction sequence, then demethylation, afforded meso-hexoestrol[3,4-D2]. Dehydration of (3RS,4SR)-3,4-bis(p-methoxyphenyl)hexan-2ξ-ol[3,4-D2] with phosphoryl trichloride in pyridine gave 3,4-bis(p-methoxyphenyl)hex-2-ene[4-D]. Reduction of erythro-2,3-bis(p-methoxy- phenyl)valeronitrile[3-D] to the corresponding amine followed by quaternization and Hofmann elimination afforded 2,3-bis(p-methoxypheny1)pent-1-ene[3-D].

Squaramide-catalysed asymmetric cascade reactions of 2,3-dioxopyrrolidines with 3-chlorooxindoles

2020 ◽  
Vol 18 (8) ◽  
pp. 1647-1656 ◽  
Author(s):  
Jiang-Bo Wen ◽  
Da-Ming Du
Keyword(s):  
Michael Addition ◽  
Cascade Reactions ◽  
Cascade Reaction ◽  
Spiro Compounds ◽  
Asymmetric Michael Addition ◽  
High Yields

An efficient squaramide-catalysed asymmetric Michael addition/cyclization cascade reaction of 3-chlorooxindoles with 2,3-dioxopyrrolidines produced the corresponding chiral spiro-compounds in high yields with excellent stereoselectivities.

Preparation of nitrogen heterocycles from aromatic amines using tris(isopropylthio)cyclopropenyl cation as a three-carbon building block

1992 ◽  
Vol 70 (1) ◽  
pp. 1-4 ◽  
Author(s):  
Hideo Kojima ◽  
Noboru Matsumura ◽  
Hiroo Inoue
Keyword(s):  
Dimethyl Sulfoxide ◽  
Intramolecular Cyclization ◽  
Building Block ◽  
Aromatic Amines ◽  
Nitrogen Heterocycles ◽  
Sodium Hydride ◽  
Iminium Salts ◽  
High Yields

Quinolines (2 and 3) and naphthazepines (8 and 9) are prepared in high yields by the reaction of tris(isopropylthio)-cyclopropenylium perchlorate (1) with anilines and 1-naphthylamines, respectively, under nitrogen in N,N-dimethylformamide at 80–85 °C. The reactions are proven to proceed through the intermediary formation of iminium salts (5, 10, and 11) derived from 1 and amines. The reaction of 1 with pyrrole and indole in dimethyl sulfoxide, containing sodium hydride, at 25 °C gives 5,6,7-tris(isopropylthio)-1H-pyrrolizine (12) and 1,2,3-tris(isopropylthio)-9H-fluorazene (14), respectively, in high yields by intramolecular cyclization of a vinylcarbene intermediate. The possible pathway for the formation of these nitrogen heterocycles is proposed. Keywords: cyclopropenyl cation, aromatic amines, nitrogen heterocycles, three-carbon building block.

Synthesis of N-Methylamino Acid Derivatives from Amino Acid Derivatives using Sodium Hydride/Methyl Iodide

1971 ◽  
Vol 49 (11) ◽  
pp. 1968-1971 ◽  
Author(s):  
John R. Coggins ◽  
N. Leo Benoiton
Keyword(s):  
Amino Acid ◽  
Methyl Iodide ◽  
Methyl Esters ◽  
Acid Methyl Ester ◽  
Sodium Hydride ◽  
Amino Acid Derivative ◽  
Acid Methyl ◽  
High Yields ◽  
Optically Pure ◽  
Derivatives Of

Reaction of N-acetyl-, N-benzoyl-, and N-carbobenzoxy derivatives of aliphatic amino acids with sodium hydride/methyl iodide in tetrahydrofuran containing dimethylformamide at 80° gave the corresponding N-methylamino acid methyl esters as oils in high yields. Saponification of these gave the N-protected-N-methylamino acids, and decarbobenzoxylation gave the N-methylamino acid methyl ester hydrobomides. The products are essentially optically pure and free of unmethylated amino acid derivative.

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.

A Simple Method for Preparing Fibrinogen

1966 ◽  
Vol 16 (01/02) ◽  
pp. 198-206 ◽  
Author(s):  
W Straughn ◽  
R. H Wagner
Keyword(s):  
Barium Sulfate ◽  
Caproic Acid ◽  
Aminobutyric Acid ◽  
Gamma Aminobutyric Acid ◽  
Human Fibrinogen ◽  
Simple Method ◽  
High Yields ◽  
Marked Stability

SummaryA simple new procedure is reported for the isolation of canine, bovine, porcine, and human fibrinogen. Two molar β-alanine is used to precipitate fibrinogen from barium sulfate adsorbed plasma. The procedure is characterized by dependability and high yields. The material is 95% to 98% clottable protein but still contains impurities such as plasminogen and fibrin-stabilizing factor. Plasminogen may be removed by adsorption with charcoal. The fibrinogen preparations exhibit marked stability to freezing, lyophilization, and dialysis. Epsilon-amino-n-caproic acid and gamma-aminobutyric acid which were also studied have the property of precipitating proteins from plasma but lack the specificity for fibrinogen found with β-alanine.

A Novel Method for the Rapid Purification of Human and Rat Fibrin(OGEN) Degradation Products in High Yields

1979 ◽  
Author(s):  
W. Nieuwenhuizen ◽  
I. A. M. van Ruijven-Vermeer ◽  
F. Haverkate ◽  
G. Timan
Keyword(s):  
Degradation Products ◽  
Complete Separation ◽  
Purification Method ◽  
Amino Terminal ◽  
Novel Method ◽  
Rapid Purification ◽  
The One ◽  
High Yields ◽  
Size Heterogeneity ◽  
D Dimer

A novel method will be described for the preparation and purification of fibrin(ogen) degradation products in high yields. The high yields are due to two factors. on the one hand an improved preparation method in which the size heterogeneity of the degradation products D is strongly reduced by plasmin digestion at well-controlled calcium concentrations. At calcium concentrations of 2mM exclusively D fragments, M.W.= 93-000 (Dcate) were formed; in the presence of 1OmM EGTA only fragments M.W.= 80.000 (D EGTA) were formed as described. on the other hand a new purification method, which includes Sephadex G-200 filtration to purify the D:E complexes and separation of the D and E fragments by a 16 hrs. preparative isoelectric focussing. The latter step gives a complete separation of D (fragments) (pH = 6.5) and E fragments (at pH = 4.5) without any overlap, thus allowing a nearly 100% recovery in this step. The overall recoveries are around 75% of the theoretical values. These recoveries are superior to those of existing procedures. Moreover the conditions of this purification procedure are very mild and probably do not affect the native configuration of the products. Amino-terminal amino acids of human Dcate, D EGTA and D-dimer are identical i.e. val, asx and ser. in the ratgly, asx and ser were found. E 1% for rat Dcate=17-8 for rat D EGTA=16.2 and for rat D- dimer=l8.3. for the corresponding human fragments, these values were all 20.0 ± 0.2.

Studi Awal Geologi di Daerah Beruang Kanan Kabupaten Gunung Mas Propinsi Kalimantan Tengah

PROMINE ◽  
2018 ◽  
Vol 6 (1) ◽  
pp. 1-11
Author(s):  
Retno Anjarwati ◽  
Arifudin Idrus ◽  
Lucas Donny Setijadji
Keyword(s):  
Gold Mineralization ◽  
Volcanic Rocks ◽  
Gold Deposits ◽  
Central Kalimantan ◽  
Magmatic Arc ◽  
Tertiary Sediment ◽  
Copper Gold ◽  
Regional Tectonic ◽  
Mineralization Processes ◽  
High Yields

The regional tectonic conditions of the KSK Contract of Work are located in the mid-Tertiary magmatic arc (Carlile and Mitchell, 1994) which host a number of epithermal gold deposits (eg, Kelian, Indon, Muro) and significant prospects such as Muyup, Masupa Ria, Gunung Mas and Mirah. Copper-gold mineralization in the KSK Contract of Work is associated with a number of intrusions that have occupied the shallow-scale crust at the Mesozoic metamorphic intercellular junction to the south and continuously into the Lower Tertiary sediment toward the water. This intrusion is interpreted to be part of the Oligocene arc of Central Kalimantan (in Carlile and Mitchell 1994) Volcanic rocks and associated volcanoes are older than intrusions, possibly aged Cretaceous and exposed together with all three contacts (Carlile and Mitchell, 1994) some researchers contribute details about the geological and mineralogical background, and some papers for that are published for the Beruang Kanan region and beyond but no one can confirm the genesis type of the Beruang Kanan region The mineralization of the Beruang Kanan area is generally composed by high yields of epithermal sulphide mineralization. with Cu-Au mineralization This high epithermal sulphide deposition coats the upper part of the Cu-Au porphyry precipitate associated with mineralization processes that are generally controlled by the structure

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