Microwave-assisted synthesis of HYNIC protected analogue for 99mTc labeled antibody.

We described herein a simple and efficient microwave assisted synthesis of HYNIC analogues. Two different activated esters of HYNIC, the hydrazine protected with a trifluoroacetyl group (5) and the free hydrazine (6) were conjugated to the monoclonal antibody Nimotuzumab. Technetium-99m radiolabeling of Nimotuzumab was achieved with high efficiency using 5 and 6 derivates. The NHS-HYNIC-Tfa derivate allowed better labeling yields during longer times of preservation of the conjugated antibody.