摘要 |
<p>The invention relates to a process for preparing a compound represented by the formula 1 which compound may optionally be further mono- or di- substituted with halogen atoms, alkyl groups having 1 to 4 C- atoms and/or alkoxy groups having 1 to 4 C- atoms, wherein R is methyl or ethyl group, comprising the step of: contacting a corresponding compound represented by the formula 2 which compound is not further substituted or further mono- or di- substituted in corresponding positions with halogen atoms, alkyl groups having 1 to 4 C- atoms and/or alkoxy groups having a to 4 C-atoms, with an alkylating agent, wherein the alkylating agent is a compound of the formula (RO)2SO2 or RX, wherein R has the above meaning and X is halogen, in the presence of a bis-quaternary ammonium salt or a polymeric quaternary ammonium salt, in a two-phase system of an aqueous solution of a base and an organic solvent.</p> |