Synthesis of 5- and 6-Carboxy-X-rhodamines

2015-12-16T15:23:39Z (GMT) by Md. Jashim Uddin Lawrence J. Marnett
An efficient route is reported to 5- and 6-carboxy-X-rhodamines (compounds 1 and 2) that contain multiple n-propylene or γ,γ-dimethylpropylene groups bridging terminal nitrogen atoms and the central xanthene core. Gram quantities of these dyes are synthesized from inexpensive starting materials. The isolated products are activated by selective transformation of the carboxylic acid group into N-hydroxysuccinimidyl esters in situ and then conjugated with an amino group of a molecule of interest.