摘要:
A method is described for the synthesis of oxetan-2-ones comprising protection of the hydroxy group of an hydroxy ester with an acid-labile acetal protecting group, reduction of this O-protected hydroxy ester to an O-protected hydroxy aldehyde, condensation of this aldehyde with a metal enolate of an activated carboxylic acid derivative and spontaneous deprotection of the hydroxy group during the acidic workup procedure. Using the new O-protected hydroxy aldehydes as intermediates the oxetan-2-ones can be obtained after separation in diastereomerically and enantiomerically pure form, in a remarkably reduced number of steps, and in a significantly improved overall yield.
摘要:
The present invention relates to compounds of formula (I), ##STR1## wherein A is an optionally substituted phenyl naphthyl, pyridyl, pyrazinyl, pyridazinyl, pyrimidyl, thienyl, thiazolyl, oxazolyl, thiadiazolyl having at least two adjacent ring carbon atoms or a bicyclic ring system, provided that the --CH(R.sup.3)N(R.sup.2)B--R.sup.1 and --OCH(R.sup.4 --)--D linking groups arm positioned in a 1,2 relationship to one another on ring carbon atoms and the ring atom positioned ortho to the --OCHR.sup.4 -- linking group (and therefore in the 3-position relative to the --CHR.sup.3 NR.sup.2 -- linking group) is not substituted; B is an optionally substituted ring system; D is an optionally substituted ring system; R.sup.1 is a variety of group as defined in the description; R.sup.2 is hydrogen, C.sub.1-6 alkyl, C.sub.2-6 alkenyl, C.sub.2-6 alkynyl, phenylC.sub.1-3 alkyl or 5- or 6-membered heteroarylC.sub.1-3 alkyl; R.sup.3 is hydrogen or C.sub.1-4 alkyl; R.sup.4 is hydrogen or C.sub.1-4 alkyl; and N-oxides of NR.sup.2 where chemically possible; and S-oxides of sulphur containing rings were chemically possible; and pharmaceutically acceptable salts and in vivo hydrolysable esters and amides thereof. Process for their preparation, intermediates in theirpreparation, their use as therapeutic agents and pharmaceutical compositions containing them.
摘要:
The invention is directed to a process for reducing or reductively cleaving an organic compound susceptible to dissolving metal reduction comprising exposing the organic compound to a solution of lithium in a polyamine including at least two amino groups, selected from the group consisting of primary and secondary amino groups and mixtures thereof, e.g. ethylenediamine and R--NH.sub.2, optionally containing a lower alkyl alcohol, wherein R is chosen from the group consisting of ethyl, propyl, and butyl, including all straight and branched chain isomers thereof, for a time sufficient to effect reduction.
摘要:
A perfluoroalkylation reactant and a process for its use involving reactions with nucleophilic substrates. The perfluoroalkylation reactant comprises:a) a perfluoroalkanesulphinate; and,b) a monoelectronic oxidizing system whose redox potential is greater than or equal to 1.20 V relative to the so-called saturated calomel reference electrode (SCE: Hg/HgCl.sub.2).
摘要:
Fluorinated aldehydes are made by reacting a fluorinated acyl chloride with a silicon hydride in the presence of palladium. Also disclosed are fluorinated ether aldehydes and their polymers, a process for making fluorinated aldehydes polymers using titanium or aluminum alkoxide catalysts, and a process for endcapping fluorinated polymers using perfluoroallyl fluorosulfate or fluorine.
摘要:
Fluorinated aldehydes are made by reacting a fluorinated acyl chloride with a silicon hydride in the presence of palladium. Also disclosed are fluorinated ether aldehydes and their polymers, a process for making fluorinated aldehydes polymers using titanium or aluminum alkoxide catalysts, and a process for endcapping fluorinated polymers using perfluoroallyl fluorosulfate or fluorine.
摘要:
An optically active 5-methylenedioxolan-4-one derivative is subjected to Diels-Alder reaction with cyclopentadiene, and the resulting Diels-Alder reaction product is hydrolyzed to convert it into an optically active 2-hydroxynorbornene-2-carboxylic acid, which is then subjected to catalytic hydrogenation to form an optically active 2-hydroxynorbornane-2-carboxylic acid. The hydroxycarboxylic acid is subjected to oxidative decarboxylation to obtain an optically active 2-norbornanone.
摘要:
A method for synthesizing enantiomerically enriched chemical intermediates with predetermined chirality is described. The method comprises formation of a pseudoephedrine amide, followed by stereoselective alkylation at the alpha carbon. The chiral auxiliary can then be cleaved off, affording chiral end products useful for further transformations. The enantiomeric enrichment of the chiral end products may exceed 98%, and the chiral auxiliary can be recovered. Novel amides of pseudoephedrine used in this method are also disclosed.
摘要:
The invention relates to benzylindane phospholipase A.sub.2 inhibitors, pharmaceutical compositions containing them, and methods of treating phospholipase A.sub.2 -mediated conditions in mammals by administration of a therapeutically effective amount of such a benzylindane phospholipase A.sub.2 inhibitor including the representative example: ##STR1##
摘要:
The invention relates to the preparation of a benzaldehyde by hydrogenation of a corresponding benzoic acid in the gas phase in the presence of a manganese containing catalyst on an acid carrier. The invention is characterized in that use is made of a catalyst prepared by:(a) coprecipitation, at a pH between 7 and 10, of a manganese salt and a salt from which an acid carrier is formed,(b) subsequent calcination at a temperature between 300.degree. and 700.degree. C.,(c) followed by reduction with a hydrogen containing gas mixture.Preferably the catalyst contains oxides of aluminum, zirconium, titanium, hafnium and/or niobium.