PET studies of potential chemotherapeutic agents—X. Synthesis of “no-carrier-added” (11C)-HECNU: The hydroxyethyl analog of the chemotherapeutic agent BCNU

11CO bonds made easily for positron emission tomography radiopharmaceuticals

“…Technical problems and a certain propensity to failure were often reported together with relatively low measured specific radioactivities. 103,104 …”

“…Technical problems and a certain propensity to failure were often reported together with relatively low measured specific radioactivities. 103,104 Beginning in the 1980s, [ 11 C]CO was abandoned for producing [ 11 C]COCl 2 and four alternative methods were described using [ 11 C]CCl 4 as the common intermediate. [105][106][107][108][109][110][111][112] Invariably, the first step consisted of mixing [ 11 C]CH 4 with a certain amount of Cl 2 and passing the mixture through a heated glass or quartz tube filled with cupric chloride on pumice stone, 105,106 empty 109,110,112 or filled with glass beads.…”

Synthesis and Application of Isocyanates Radiolabeled with Carbon‐11

“…Carbon-11 labeled phosgene [8] has been used to prepare [ 11 C]isocyanates by reaction with amines in the presence of base. [9][10][11][12] In particular Brown et al [13] devised a clever way to overcome the formation of symmetrical [ 11 C]ureas, a common but undesirable side-reaction, by utilizing N-sulfinylamines as precursors. While reactive enough to add to phosgene, N-sulfinylamines are poor nucleophiles, thus suppressing further addition of amine to the generated [ [14] .…”