Improved chemical synthesis of 1- and 5-deazariboflavin

The catalytic activity of a large class of enzymes, known as flavoenzymes, is derived by the use of cofactor flavin adenine dinucleotide (FAD). The improved chemical syntheses for the preparation of the two key analogues, 5-deazariboflavin and 1-deazariboflavin are reported.