Process for preparing 4.6-bis(difluoromethoxy)pyrimidine derivatives
AssigneeLonza Ltd.
InventorsAndreas Naepfli, Jean-Paul Roduit, Alain Wellig
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Abstract
A process for preparing 4,6-bis(difluoromethoxy)pyrimidine derivatives of the general formula: ##STR1## wherein R is a C.sub.1-4 -alkyl or optionally substituted phenyl or benzyl, proceeding from the corresponding 4,6-dihydroxypyrimidine dialkali-metal salt. In the process, the educt is reacted under pressure with chlorodifluoromethane in a solvent selected from the group consisting of the ketones, in the presence of a base and a phase-transfer catalyst and in the presence of 40 to 100 mol per mol of water of the 4,6-dihydroxypyrimidine dialkali-metal salt to form the final product.
Claims15
A process for preparing a 4,6-bis(difluoromethoxy)pyrimidine derivative of formula:
- ##STR4## wherein R is C.sub.1-4 -alkyl, optionally substituted phenyl or optionally substituted benzyl, comprising reacting a 4,6-dihydroxypyrimidine dialkali-metal salt of formula:
- ##STR5## wherein R has the above-stated meaning and M is an alkali-metal atom, under pressure with chlorodifluoromethane in a solvent selected from the group consisting of the ketones, in the presence of a base and a phase-transfer catalyst and in the presence of 40 to 100 mol of water per mol of the 4,6-dihydroxypyrimidine dialkali-metal salt of formula II to form the final product of formula I.
Dependencies are inferred from the claim text.