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:
Jul. 27, 1993
Filed:
May. 06, 1991
Donald A McGowan, Bedford, MA (US);
Paulina P Garcia, Arlington, MA (US);
John W Lee, Still River, MA (US);
Thomas K Spencer, Lexena, KS (US);
Stephen J Telfer, Arlington, MA (US);
Michael J Zuraw, Arlington, MA (US);
Polaroid Corporation, Cambridge, MA (US);
Abstract
Squarylium compounds of the formula: ##STR1## wherein Q.sup.1 and Q.sup.2 are each independently a pyrylium, thiopyrylium, selenopyrylium, benzpyrylium, benzthiopyrylium or benzselenopyrylium nucleus, and R.sup.1 and R.sup.2 are each independently an aliphatic or cycloaliphatic group, can be prepared by reacting a squaric acid derivative of the formula: ##STR2## with a compound of the formula Q.sup.2 CH.sub.2 R.sup.2 in the presence of a base. The derivatives of Formula II may be prepared by condensing a 2,3,4,4-tetrahalocyclobut-2-en-1-one with a compound of the formula Q.sup.1 CH.sub.2 R.sup.1 in the presence of a base to produce a compound of the formula: ##STR3## wherein Q.sup.1 and R.sup.1 are as defined above, and X represents chlorine or bromine, and hydrolyzing the compound of Formula III. Alternatively, the derivatives of Formula II may be prepared by reacting a diester, monoacid chloride monoester or diacid chloride of squaric acid with a compound of the formula Q.sup.1 CH.sub.2 R.sup.1 in the presence of a base, followed by hydrolysis of the resultant monoacid chloride or monoester derivative of the compound of Formula II to the parent compound.