Abstract
It was found that a crystalline product (III), mp 284-289℃ (decomp), was obtained by the reaction of B_1 and formalin in the presence of sec. amine in an aqueous alkaline solution. The product (III) was treated with acid anhydride to afford the corresponding ο-acyl derivatives (IV). From chemical and physical data of III and IV, III was assumed to be a bis-type structure, 2,7,13,18-tetramethyl-6,17-diformyl-8,19-di (2-hydroxyethyl)-dipyrimido [4,5-d ; 4', 5'-m]1,10-dithia-3,7,12,16-tetraazacyclooctadeca-4,8,13,17-tetraene, consisting of molar B_1 and 2 molar formaldehyde. Depending upon its cyclic bis-type structure, III was abbreviated as cyclobismethylene-thiamine (CBMT). Formation conditions of CBMT were investigated. CBMT and its ο-acyl derivatives were proved to be little effective to promote the growth of thiamine-deficient rats.
