Studies of Labeling Methods of Vitamins K with Tritium and Carbon-14

Abstract

A labeling method with tritium at the 6th position, a biological inert position, of naphthoquinone nucleus o f vitamins K was studied.
The catalytic tritiation of 2-methyl- 6-bromonaphthalene on Pd-black was found to be successful for labeling selectively the 6th position.
The position of tritium label was confirmed by assignning the IR and NMR spectra of deuterated model compounds which were synthesized by the same procedures as tritiation. And it was also found that H₃PO₄ was more useful co-catalyst for the condensation of naphthoquinone nucleus with the side chain of vitamin K_{2 (20)} .