Process for the preparation of coumarin compounds
AssigneeEastman Kodak Company
InventorRichard H. S. Wang
Life of this patent
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Abstract
Disclosed is a three-step process for the preparation of 3-chloro-4-alkyl-7-hydroxy or alkoxycoumarin compounds starting with resorcinol or a monoalkyl ester of resorcinol and chlorinating an intermediate compound with sulfuryl chloride in the presence of acetic acid or an alkyl acetate.
Claims2
Process for the preparation of a coumarin compound having the formula ##STR5## which comprises (1) reacting a resorcinol compound having the structure ##STR6## with a .beta.-ketoester having the structure ##STR7## at elevated temperature in the presence of a catalytic amount of a protonic acid condensation catalyst and an inert solvent while distilling off reaction by-products to form an intermediate having the structure ##STR8## (2) forming a mixture of acetic acid or an alkyl acetate with the reaction mixture obtained from (1);
- and
- (3) adding sulfuryl chloride to the mixture obtained from (2) and heating the resulting mixture;
- wherein
- R.sup.1 is hydrogen or alkyl of about 1 to 8 carbon atoms;
- R.sup.2 is hydrogen or alkyl of about 1 to 6 carbon atoms, chlorine, bromine or an aryl radical;
- and
- R.sup.3 is alkyl of about 1 to 6 carbon atoms.
Dependencies are inferred from the claim text.