Table 2.

Radiotracers synthesized using vial and “in-loop” [¹¹C]CO₂-fixation

Entry	Compound	Vial methoda	“In-loop” methodb	RCP (%)e	Synthesis time (min)	Radioactivity at EOS (GBq (mCi))f	Molar radioactivity (GBq/μmol)g
		RCY(%)c, d	RCY(%)c, d
1	[11C]2	33	70 (43)h	>99	35	10.2±2.8 (276±74)	134±21
2	[11C]5	5	72 (54)h	>99	33	14.3 (387)	84
3	[11C]7	2	30 (18)h	>99	38	3.8 (102)	80

^aConditions for vial reaction. (1) Precursor 1 (0.6 μmol); primary amines 3 and 6 (110 and 150 μmol, respectively); BEMP (5 μL, 34.6 μmol), DMF (80 μL); (2) 0.2% POCl₃ (v/v) in MeCN (100 μL, 1.1 μmol); (3) secondary amine (4) in DMF (100 μL).

^bConditions for “in-loop” reaction. (1) Precursor 1 (0.3 μmol); primary amines 3 and 6 (55 and 75 μmol, respectively); BEMP (2.5 μL, 17.3 μmol), DMF (40 μL); (2) 0.2% POCl₃ (v/v) in MeCN (100 μL, 1.1 μmol); (3) secondary amine (4) in DMF (50 μL).

^cNon-isolated radiochemical yield (RCY), based on radio-HPLC analysis of the crude product.

^dExperiments were performed once (n=1).

^eRadiochemical purity (RCP) of the isolated product.

^fTotal amount of the isolated product at the end-of-synthesis.

^gMolar radioactivity of the isolated product established by HPLC.

^hThe decay-corrected radiochemical yield of the isolated product obtained after semi-preparative HPLC and formulation.