title: IMPROVED SYNTHESIS OF 10-(2-ALKYLAMINO-2-OXOETHYL)-1,4,7,10-TETRAAZACYCLODODECANE-1,4,7-TRIACETIC ACID DERIVATIVES BEARING ACID-SENSITIVE LINKERS.
abstract: Alkylation of the hydrobromide salts of 1,4,7-tris(methoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane and 1,4,7-tris(ethoxycarbonylmethyl)-1,4,7,10-tetraazacyclododecane with appropriate α-bromoacetamides, followed by hydrolysis, provides convenient access to 10-(2-alkylamino-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid derivatives that contain acid-sensitive functional groups. The utility of the method is demonstrated by improved syntheses of two known DOTA monoamides bearing acid-sensitive ω-tritylthio alkyl chains in much higher yields based on cyclen as the starting material.
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0041 USA.
authors.forename: Bhumasamudram
authors.initials: B
authors.lastname: Jagadish
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0041 USA.
authors.forename: Tarik J
authors.initials: TJ
authors.lastname: Ozumerzifon
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0041 USA.
authors.forename: Sue A
authors.initials: SA
authors.lastname: Roberts
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0041 USA.
authors.forename: Gabriel B
authors.initials: GB
authors.lastname: Hall
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721-0041 USA.
authors.forename: Eugene A
authors.initials: EA
authors.lastname: Mash
authors.affiliation: Department of Medical Imaging, University of Arizona, Tucson, AZ 85721-0041 USA ; Arizona Cancer Center, University of Arizona, Tucson, AZ 85721-0041 USA.
authors.forename: Natarajan
authors.initials: N
authors.lastname: Raghunand
keywords: Cyclen; DO3A monoamide; DOTA monoamide; medical imaging; synthesis