Process for preparation 2,6-dihydrobenzo[1:26, 4:5-6]-difuran dyes
US5189181A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 7, 1992 |
| Grant date | Feb 23, 1993 |
| Priority date | — |
| Expiry date | Jan 7, 2012 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC09B57/00
- WIPO fieldOrganic fine chemistry
- WIPO sectorChemistry
Abstract
A process for the preparation of a polycyclic dye of the Formula (1): ##STR1## by reacting a substituted acetic acid of the Formula (2): ##STR2## with a compound of the Formula (3): ##STR3## and oxidation of the intermediate leuco compound to dehydrogenate the peripheral heterocyclic rings wherein PA1 Y is an optionally substituted aromatic or heteroaromatic radical; PA1 Ring A is unsubstituted or is substituted by from one to five groups; PA1 Z is --NR.sup.1 R.sup.2 ; PA1 R.sup.1 and R.sup.2 are each independently H or are independently selected from optionally substituted alkyl, alkenyl, cycloalkyl, aralkyl, aryl and heteroaryl; or PA1 R.sup.1 and R.sup.2 together with the nitrogen atom to which they are attached form a heterocyclic ring; or PA1 R.sup.1 and R.sup.2 each independently together with the nitrogen to which they are attached and the adjacent carbon atom of Ring B form a heterocyclic ring; and PA1 X.sup.1 and X.sup.2 are each independently selected from H, halogen, optionally substituted alkyl, optionally substituted aryl, optionally substituted heteroaryl, cyano, carbamoyl, sulphamoyl, carboxylic acid and carboxylic acid ester, a process for the preparation of the sub…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.