The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 21, 1982
Filed:
Jul. 23, 1980
Nippon Kayaku Kabushiki Kaisha, Tokyo, JP;
Abstract
A novel process for producing 7-alkoxycarbonyl-6,8-dimethyl-4-hydroxymethyl-1-phthalazone, and its intermediates. 7-Alkoxycarbonyl-6,8-dimethyl-4-hydroxymethyl-1-phthalazone can be obtained by reacting substituted methylenetriphenylphosphorane with 3,5-dimethyl-4-alkoxycarbonylphthalic anhydride to obtain 6-alkoxycarbonyl-5,7-dimethyl-.DELTA..sup.3,.alpha. -substituted methylenephthalide, reacting the latter with hydrazine to obtain a phthalazone derivative, hydrolyzing the latter, halogenating the hydrolyzate to obtain 7-alkoxycarbonyl-6,8-dimethyl-4-(.alpha.-halogeno-.alpha.-substituted methyl)-1-phthalazone and then directly hydrolyzing and decarboxylating the latter or, when said 7-alkoxycarbonyl-6,8-dimethyl-4-(.alpha.-halogeno-.alpha.-substituted methyl)-1-phthalazone is 7-alkoxycarbonyl-6,8-dimethyl-1-phthalazone-4-.alpha.-halogenoacetic acid, reacting it with a carboxylic acid salt such as sodium acetate and simultaneously decarboxylating the acyloxylated compound and then hydrolyzing the decarboxylated product or firstly decarboxylating the 1-phthalazone-4-.alpha.-halogenoacetic acid derivative, reacting the decarboxylated product with said carboxylic acid salt and then hydrolyzing the reaction product or when said 7-alkoxycarbonyl-6,8-dimethyl-4-(.alpha.-halogeno-.alpha.-substituted methyl)-1-phthalazone is 7-alkoxycarbonyl-4-(.alpha.-carbamoyl-.alpha.-halogenomethyl)-6,8-dimethyl -1-phthalazone, reacting it with said carboxylic acid salt and then hydrolyzing and decarboxylating the acyloxylated compound simultaneously.