A Simple Synthesis of Amphimedine

1991 ◽  
Vol 44 (2) ◽  
pp. 277 ◽  
Author(s):  
RH Prager ◽  
C Tsopelas ◽  
T Heisler
Keyword(s):  
Acid Treatment ◽  
Polyphosphoric Acid ◽  
Simple Synthesis ◽  
Hydrazoic Acid ◽  
Short Sequence ◽  
Marine Alkaloid ◽  
Alkaline Ferricyanide

The marine alkaloid amphimedine has been synthesized by a short sequence of reactions commencing from the known indenopyridinedione (2). Reaction with 4-pyridyllithium, followed by hydrazoic acid treatment, gave 5-(4-pyridyl)-3,6-phenanthrolin-4(3H)-one (12) which was converted into the chlorophenanthroline. The methyl-substituted fluorosulfonate salt of this compound was specifically oxidized by alkaline ferricyanide. Conversion of the pyridone into the nitrile gave the precursor which was cyclized to amphimedine by polyphosphoric acid.

Studies on intramolecular alkylation. X. The acid-catalysed reactions of 5,8-Dialkoxy-1,2,3,4-tetrahydronaphthyl diazomethyl ketones

1978 ◽  
Vol 31 (7) ◽  
pp. 1561 ◽  
Author(s):  
DW Johnson ◽  
LN Mander
Keyword(s):  
Trifluoroacetic Acid ◽  
Acid Treatment ◽  
Polyphosphoric Acid ◽  
Intramolecular Alkylation ◽  
Naphthoic Acid ◽  
Acid Catalysed Reactions ◽  
Diazomethyl Ketones

5,8-Dimethoxy-3,4-dihydronaphthalen-1(2H)-one was converted into diazomethyl 5,8-dimethoxy-1,2,3,4-tetrahydro-2-naphthyl ketone (10) which, when treated with trifluoroacetic acid at 0°, gave 5,8- dimethoxy-4,4a-dihydro-3,4a-ethanonaphthalen-2(3H)-one (13), but at -15° gave 8-methoxy-1,2,3,4-tetrahydro-3,4a-ethanonaphthalene- 5(4aH),10-dione (14). 6-Methoxy-3,4-dihydronaphtha-len-1(2H)-one reacted with m-chloroperoxybenzoic acid to give 4,5-dihydro-1-benzoxepin-2(3H)-one (15) which after hydrolysis, ethylation and polyphosphoric acid treatment gave 5-ethoxy-8-methoxy-3,4-dihydronaphthalen-1(2H)-one (17). This compound was transformed into 5-ethoxy-8-hydroxy-1,2,3,4-tetrahydro-2-naphthoic acid (19) and thence to the ethoxy analogue of (14).

Synthetic studies on 5-(3,4-dimethoxyphenyl)-5,6-dihydrophenanthridin-6-ol,an analogue of perloline

1982 ◽  
Vol 35 (8) ◽  
pp. 1645 ◽  
Author(s):  
SI Clarke ◽  
RH Prager
Keyword(s):  
Title Compound ◽  
Polyphosphoric Acid ◽  
Hydrazoic Acid ◽  
Synthetic Studies

Two independent syntheses of the title compound (2), an analogue of perloline, are described. 9-(3,4-Dimethoxyphenyl)fluoren-9-ol reacted with hydrazoic acid in polyphosphoric acid to give 6-(3,4-dimethoxyphenyl)phenanthridine, the N-oxide of which was photolysed to 5-(3,4-dimethoxy-phenyl)phenanthridin-6-one (8) which was reduced to the title compound directly with sodium bis(2-methoxyethoxy)aluminium hydride ('Redal'), or by reduction to 5-(3,4-dimethoxypheny1)-5,6- dihydrophenanthridine followed by oxidation with N-bromosuccinimide. The phenanthridinone (8) was also synthesized by photolysis of the nitrone of 3,4-dimethoxy-N-fluorenylideneaniline.

Polyphosphoric acid treatment promotes bone regeneration around titanium implants

2009 ◽  
Vol 36 (5) ◽  
pp. 362-367 ◽  
Author(s):  
K. MAEKAWA ◽  
K. SHIMONO ◽  
M. OSHIMA ◽  
Y. YOSHIDA ◽  
B. VAN MEERBEEK ◽  
...  
Keyword(s):  
Bone Regeneration ◽  
Acid Treatment ◽  
Polyphosphoric Acid ◽  
Titanium Implants

Fasciaton of Pectate Elementary Fibrils

1973 ◽  
Vol 31 ◽  
pp. 60-61
Author(s):  
George F. Leeper
Keyword(s):  
Acid Treatment ◽  
Carbon Film ◽  
Final Concentration ◽  
Cellulose Microfibrils ◽  
Pectic Acid ◽  
Elementary Fibrils

Polysaccharide elementary fibrils are usually fasciated into microfibrils of from one hundred to a few hundred Angstroms wide. Cellulose microfibrils when subjected to acid treatment dissociate into component elementary fibrils. For pectic acid it was observed that variations in pH could cause a change in the fasciation of the elementary fibrils.Solutions of purified pectic acid and sodium phosphotungtate were adjusted to various pH levels with NaOH or HCl and diluted to give a final concentration of 0.5 and 1% for the polysaccharide and negative stains respectively. Micrographs were made of the samples after drying on a carbon film covered grid. The average number of elementary fibrils was determined by counting the number of elementary fibrils in each fascicle intersected by lines drawn across the micrograph.

Does anti-acid treatment influence disease progression in SSc-ILD? Data form the German SSc-network

2020 ◽  
Author(s):  
M Kreuter ◽  
F Bonella ◽  
N Blank ◽  
E Siegert ◽  
J Henes ◽  
...  
Keyword(s):  
Disease Progression ◽  
Acid Treatment ◽  
Data Form

The Diels-Alder Reaction of 2-Ethenyl-1,4-Benzodioxin: A New and Simple Synthesis of Bisaryl Ethers

Synlett ◽  
1989 ◽  
Vol 1989 (01) ◽  
pp. 30-32
Author(s):  
Thomas V. Lee ◽  
Alistair J. Leigh ◽  
Christopher B. Chapleo
Keyword(s):  
Alder Reaction ◽  
Diels Alder ◽  
Simple Synthesis ◽  
Diels Alder Reaction

Effect of valproic acid treatment on body composition, leptin and soluble leptin receptor in epileptic children

2006 ◽  
Vol 37 (06) ◽  
Author(s):  
M Rauchenzauner ◽  
E Haberlandt ◽  
S Scholl-Bürgi ◽  
D Karall ◽  
E Schönherr ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Body Composition ◽  
Acid Treatment ◽  
Leptin Receptor ◽  
Soluble Leptin Receptor ◽  
Epileptic Children
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