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:
Nov. 16, 1982
Filed:
Aug. 04, 1980
Stanley M Bloom, Waban, MA (US);
Alan L Borror, Lexington, MA (US);
James W Foley, Andover, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
In one aspect, this invention relates to a method of synthesizing certain 3-(4'-OH-carbocyclic aryl)-3-(carbocyclic aryl)-2,3-dihydrobenz[d]isothiazole-1,1-dioxides (and -2,3-dihydronaphtho[1,8-de]-1,2-thiazine-1,1-dioxides) by reacting a 3-(4'-OP-carbocyclic aryl)-3-(carbocyclic aryl)-2,3-dihydrobenz[d]isothiazole-1,1-dioxide (or a 3-(4'-OP-carbocyclic aryl)-3-(carbocyclic aryl)-2,3-dihydronaphtho[1,8-de]-1,2-thiazine-1,1-dioxide) wherein P is a protecting group with a carboxylic acid halide in pyridine to yield the corresponding 2-carbonyl derivative followed by removing the protecting group with weak acid to give the product. Optionally, the acylation step may be carried out by sequentially reacting the starting compound with an alkali metal hydride to give the corresponding 2-alkali metal salt and then reacting with the carboxylic acid halide in a suitable inert organic solvent. The products produced comprise phenol and 1-naphthol sulfam(na)phthaleins useful, for example, as photographic optical filter agents and filter agent precursors. In another aspect, the present invention relates to the carbonyl-substituted and alkali metal-substituted 2,3-dihydrobenz[d]isothiazole-1,1-dioxides and 2,3-dihydronaphtho[1,8-de]-1,2-thiazine-1,1-dioxides produced as intermediates in the above synthesis.