- Cleavage of carbon-sulfur bonds in the synthesis of α-haloalkyl carbonates
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α-Chloroalkyl and α-bromoalkyl carbonates have been prepared by cleavage of α-arylthioalkyl carbonates with sulfuryl chloride or bromine, respectively. The α-arylthioalkyl carbonates are prepared by reaction of the hemithioacetal 1 with chloroformates or by a destannylative tin-Pummerer rearrangement of α-stannyl sulfoxides. Acta Chemica Scandinavica 1996.
- Hatlelid, Jostein,Benneche, Tore,Undheim, Kjell
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p. 1041 - 1044
(2007/10/03)
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- Process for the manufacture of 1-bromoalkyl hydrocarbyl carbonates
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The invention relates to a new process for the preparation of 1-bromoalkyl hydrocarbyl carbonates. The carbonates according to the invention are prepared by reacting an alpha-chlorinated carbonate of formula STR1 with an anhydrous brominated compound of formula ZBr in which Z represents hydrogen, the group (CH3)3 -Si-, the group STR2 or bromine if R2 is other than an aromatic radical, in the presence of a catalyst chosen from the group consisting of heteroaromatic amines, quaternary ammonium or phosphonium halides, hexasubstituted guanidinium halides, alkaline earth metal halides or alkali metal halides in combination with a complexing agent for their cation. The carbonates according to the invention find their preferential applications as blocking agents for some antibiotics or as agents for the synthesis of phosphorus-containing carbonates which can be used as insecticides.
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- Preparation of 1'-ethoxycarbonyl-oxyethyl esters of penicillins
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Process for the preparation of 1'-ethoxy carbonyloxy ethyl esters of penicillins, wherein a compound of the formula STR1 in which A is phenyl, phenoxy or 4-hydroxyphenyl, B is hydrogen, an amino group or a protected amino group and Z is hydrogen or a cation selected from the group of alkali metal, tri (lower alkyl ) ammonium and tetra (lower alkyl) ammonium, is reacted with 1-bromoethyl ethyl carbonate in an organic solvent and when B is a protected amino group the protecting group is split off to yield a primary amino group. There are also provided novel compounds of the formula STR2 in which Ph is phenyl and R is CH3 -- or C2 H5 --.
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- Ethoxycarbonyloxy ethyl esters of non-steroidal anti-inflammatory carboxylic acids and pharmaceutical compositions thereof
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Novel esters of the general formula STR1 in which STR2 is the acyl residue of a non-steroidal anti-inflammatory compound containing a carboxylic acid function. The novel esters are prepared by reacting an acide R--COOH when R is as above, with 1-haloethyl ethyl carbonate. There are also provided pharmaceutical compositions containing any of the said novel esters.
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- Novel androstane-17β-carboxylic acid esters
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The invention refers to compounds having anti-inflammatory activity characterized by the formula STR1 or a stereoisomeric component thereof, in which formula X1 represents a hydrogen, chlorine, bromine or fluorine atom; X2 represents a hydrogen, chlorine, bromine or fluorine atom; R1 represents a β-hydroxy group, a β-chlorine atom or an oxo group; R2 represents a hydrogen atom, a methylene group or an α- or β-methyl group; R3 represents a hydrogen atom or an acyl group of 1 through 8 carbon atoms; R4 represents a hydrogen atom, a (C1 -C5) alkyl group or a phenyl group; R5 represents a hydrogen atom, a (C1 -C5) alkyl group or a phenyl group; Y represents either CR7 R8, O, S or NR9, where R7, R8 and R9 are selected from hydrogen or from straight or branched hydrocarbon chains having 1-8 carbon atoms or from a phenyl group. R6 represents a hydrogen; a methyl group; a phenyl or an alkenyl or cycloalkylene group optionally substituted by alkyl, nitro, carboxy, alkoxy, halogen, cyano, carbalkoxy and trifluoromethyl group(s); a (C1 -C5) alkyl group substituted by at least one halogen atom; a saturated or unsaturated carbocyclic or heterocyclic (O, S, N) ring system containing 3-10 atoms in the ring system; a C1 alkyl group substituted by either one or two alicyclic or aromatic 3,4,5 or 6-numbered ring system(s) or one, two or three straight or branched alkyl or alkenyl group(s) of 1 through 18 carbon atoms; and represents a single or double bond. The invention also refers to a process and intermediates for the preparation of these compounds, a pharmaceutical preparation containing one of the compounds and a method for the treatment of inflammatory conditions.
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- NOVEL CHLORIDE TO BROMIDE EXCHANGE: PREPARATION OF 1-BROMOALKYL CARBONATES
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A new method is described for the synthesis of 1-bromoalkyl carbonates which consists of reacting the corresponding 1-chloroalkyl carbonate with a volatile electrophilic bromine containing reagent (E-Br) and a catalyst.The equilibrium is driven to product by removal of the E-Cl formed.
- Senet, Jean-Pierre,Sennyey, Gerard,Wooden, Gary P.
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p. 1525 - 1530
(2007/10/02)
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- Process for the preparation of 1-bromoethyl hydrocarbonyl carbonates and new 1-bromoethyl hydrocarbonyl carbonates
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The invention relates to a process for the preparation of 1-bromoethyl hydrocarbonyl carbonates, characterized in that anhydrous hydrobromic acid is reacted with a vinyl hydrocarbonyl carbonate of formula STR1 in which R denotes a saturated, substituted or unsubstituted C1 -C12 aliphatic radical or C5 -C24 alicyclic radical, or a substituted or unsubstituted aromatic radical, at a temperature between 10° and 100° C. The invention also relates to the new 1-bromoethyl hydrocarbonyl carbonates of formula: STR2 These carbonates are particularly sought after for introducing a carbonate group into a molecule.
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- Methods for the preparation of α-bromodiethylcarbonate
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The novel compound α-bromodiethylcarbonate, novel methods for the preparation thereof, its use in the preparation of 1-ethoxycarbonyloxyethyl esters of penicillins and cephalosporins, and improvements in the method for preparing such esters.
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- 1'-ethoxycarbonyloxyethyl ester of valproic acid, its preparation and pharmaceutical compositions containing it
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1'-Ethoxycarbonyloxyethyl ester of di-n-propylacetic acid, also known as valproic acid. The novel compound is prepared by reacting valproic acid with 1-haloethyl ethyl carbonate. There are also provided pharmaceutical compositions for oral administration containing the said ester.
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