Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
142 words
Method of preparing erythromycin A cyclic 11,12-carbonate by transesterification of ethylene carbonate, using dehydrated erythromycin or its salts, characterized in that the transesterification process of cyclic 1,2-diole and 1,3-diole carbonates in an anhydrous organic solvent, advantageously either in toluene, in acetone or in an anhydrous cyclic diole carbonate, is performed in the presence of either a quarternary ammonium or phosphonium compound or of one of these compounds as a PTC catalyst with addition of either an inorganic salt, an alkali metal or alkaline earth metal hydroxide or oxide or their mixture or else the process of esterification is performed in the presence of a catalyst of the PTC type, such as a crown ether or a cryptand with the addition of the . above mentioned inorganic compounds or of their mixture, the obtained erythromycin A cyclic 11,12-carbonate being subsequently separated and purified.
Claim 2
Dependent Claim
142 words
Method of preparing erythromycin A cyclic 11,12-carbonate by transesterification of ethylene carbonate, using dehydrated erythromycin or its salts, characterized in that the transesterification process of cyclic 1,2-diole and 1,3-diole carbonates in an anhydrous organic solvent, advantageously either in toluene, in acetone or in an anhydrous cyclic diole carbonate, is performed in the presence of either a quarternary ammonium or phosphonium compound or of one of these compounds as a PTC catalyst with addition of either an inorganic salt, an alkali metal or alkaline earth metal hydroxide or oxide or their mixture or else the process of esterification is performed in the presence of a catalyst of the PTC type, such as a crown ether or a cryptand with the addition of the . above mentioned inorganic compounds or of their mixture, the obtained erythromycin A cyclic 11,12-carbonate being subsequently separated and purified.
Claim 3
Dependent Claim
26 words
Method according to claim 1, characterized in that in the process of transesterifioation there are used cyclic 1,2-diole carbonates, advantageously ethylene carbonate or propylene carb-, onate.
Claim 4
Dependent Claim
21 words
Method according to claim 1, characterized in that in the process'of transesterification there are used cyclic 1,3-diole carbonates, advantageously trimethylene carbonate.
Claim 5
Dependent Claim
53 words
Method according to claim 1, characterized in that as a quarternary ammonium compound there are advantageously used either triethylbenzylammonium chloride, tetrabutylammonium bromide, trioctylmethylammonium chloride with addition of either an inorganic salt, of an alkali metal or an alkaline earth metal hydroxide or oxide or of their mixture or triethylbenzylammonium hydroxide or carbonate alone.
Claim 6
Dependent Claim
48 words
Method according to claim 1, characterized in that as a phosphonium compound there is advantageously used either tetrabutylphosphonium chloride with addition of either an inorganic salt, of an alkali metal or alkaline earth metal hydroxide or oxide or of their mixture or tetre- butylphosphonium hydroxide or carbonate alone.
Claim 7
Dependent Claim
28 words
Method according to claim 1, characterized in that as a -crown ether there is advantageously used ether containing 12 carbon atoms and . 6 oxygen atoms, named 1,4,7,10,13,16-hexaoxacyclo-octadecane.
Claim 8
Dependent Claim
17 words
Method according to claim 1, characterized in that as a cryptand there is advantageously used 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo- [8,8,8]hexacosane.