| 摘要 |
<p>The invention relates to organic chemistry. It relates to a process for the preparation of methyl (+/-)-3-ethyl-2,3,3a,4-tetrahydro-1H-indol[3,2,1-de][1,5]naphthyridine -6-carboxylate of general formula (I): <IMAGE> characterised in that the compounds of general formula II, defined in the preceding description, are reacted with ethyl iodide during a heterogeneous phase alkylation reaction, catalysed by a quaternary ammonium salt, such as tetraethylammonium bromide, in a polar solvent formed by a 50 % mixture of dimethyl sulphoxide and an aqueous sodium hydroxide solution, with vigorous stirring at a temperature of 20 DEG C and for a time of 24 hours, to then hydrolyse the reaction and to extract the desired product with dichloromethane, the product being purified by recrystallisation from acetone. Use by the pharmaceutical industry.</p> |
