Studies of Crystalline Vitamin B₁. XVI. Identification of the Pyrimidine Portion

Abstract

The ultraviolet absorption of all of the compounds was measured with a Hilger "Spekker" Photometer in conjunction with a Hilger E316 spectrograph. The source was a tungsten steel spark in some cases and a wide aperr ture hydrogen discharge tube in others. Either source was satisfactory. The Spekker photometer gave much more satisfactory results than the rotating sector used for earlier work.8 Eastman d. c. Ortho and Cramer Contrast plates were both used with success. Solutions were in distilled water unless otherwise indicated.We wish to express our gratitude to Mr. D. F. Hayman and Mr. S. Adler for the micro-analyses, to Dr. Joseph K. Cline for the preparation of 2-methyl-6-oxy-and 2-methyl-6-aminopyrimidines, to Mr. R. E. Waterman for the pVL determinations and to Dr. . T. Clarke for the use of facilities in preparing some of the spectrograms. (9) Wintersteiner, Williams and Ruehle, This Journal, 57, Ó17 (1935). Summary 1. Methods of preparation are given for all of the previously unknown mono-and di-C-methyl derivatives of 0-oxy and 6-aminopyrimidine.2. The ultraviolet absorption is given of both complete series including the non-alkylated members.3. Addition of acid modifies the absorption of the 6-amino pyrimidines by reducing the prominence of the longer wave length band; alkali tends to equalize the prominence of the two bands.4. The absorption of aminosulfonic acid from the vitamin reveals the influence of the acidity of the sulfonic group and is affected by alkali in a similar manner as non-sulfonated 6-aminopyrimidines.

Thiamin Diphosphate Catalysis: Enzymic and Nonenzymic Covalent Intermediates

“…Breslow’s proposed ionization site was ruled out when Westheimer showed that neither thiamin (in nonenzymic reactions) nor TDP (in enzymic reactions) incorporate deuterium from solvent deuterium oxide at the methylene bridge position, a condition required by the formation of the carbanion. Westheimer’s analysis involved cleaving thiamin with bisulfite by Williams’ procedure , and mass analysis of the resulting methanesulfonic acid derivative of the pyrimidine of thiamin (Scheme ).…”

Reactions of Organic and Organometallic Compounds with Solutions of Metals in Liquid Ammonia.

“…The amidosulfonic acid derived from vitamin Bi reacts with sodium in ammonia to form low yields of 2,5-dimethyl-6-aminopyrimidine (81,424).…”

Ammonolysis in Liquid Ammonia.

“…to form diaminogossypol (191). Thiamine or vitamin Bi is split by liquid ammonia at room temperature into two fragments (46,278)…”