Squarylium compounds, and processes and intermediates for the synthesis of these compounds
US5231190A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 6, 1991 |
| Grant date | Jul 27, 1993 |
| Priority date | — |
| Expiry date | May 6, 2011 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11B7/246
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.