摘要 |
1. A process for the preparation of beta-methyldigoxin by the selective monomethylation of digoxin with dimethyl sulphate in a dimethylformamide/toluene mixture as the solvent, in the presence of a basic strontium compound and, if appropriate, of an inert inorganic adsorbent, and purification of the methylation product by column chromatography on SiO2 with a mixture of chlorohydrocarbon and a lower aliphatic alcohol, characterised in that, per mole of digoxin, 1 to 3 moles of strontium hydroxide octahydrate are used as the basic strontium compound, and 1 to 3 moles of an oxide, silicate or phosphate of an element of the 2nd, 3rd, 4th or 5th main group or subgroup of Mendeleev's periodic table, with a water content of up to 20% by weight, are used as the inert organic adsorbent which may be present, and the reaction is carried out at temperatures of - 15 degrees C to 15 degrees C. |