Bromoacetic Acid → HCID 67960759, compound

Participants

Reaction Steps

Scheme 3 illustrates an example of a method that can be used to produce a compound of formula (XVIb). This method involves cyclizing 2,2′-oxybis(ethane-2,1-diyl) bis(4-methylbenzenesulfonate) (XXVIII) with (XXII) in DMF to produce 5-(4-nitrobenzyl)-1-oxa-4,7,10-triazacyclododecane-4,7,10-triyl tris(4-methylbenzenesulfonate) (XXIX), followed by deprotection and alkylation of (XXIX) using bromoacetic acid to yield 2,2′,2″-(5-(4-nitrobenzyl)-1-oxa-4,7,10-triazacyclododecane-4,7,10-triyl)triacetic acid (XXX). Hydrogenation of the nitro group of (XXX) is then achieved using 10% palladium on carbon catalyst at ambient pressure to give aniline intermediate 2,2′,2″-(5-(4-aminobenzyl)-1-oxa-4,7,10-triazacyclododecane-4,7,10-triyl)triacetic acid (XXXI). Conversion of (XXXI) to the reactive electrophilic isothiocyanate 2,2′,2″-(5-(4-isothiocyanatobenzyl)-1-oxa-4,7,10-triazacyclododecane-4,7,10-triyl)triacetic acid (XXXII) is carried out using a 2-phase reaction medium with chloroform/water and thiophosgene.

Provenance & Evidence