130256-61-0Relevant articles and documents
Glorination of Pyrimidines. Part 2. Mechanistic Aspects of the Reaction of Acetyl Hypofluorite with Uracil and Cytosine Derivatives
Visser, W. M. Gerard,Herder, E. Renella,Kanter, Frans J. J. de,Herscheid D. M. Jacobus
, p. 1203 - 1208 (2007/10/02)
The reaction of acetyl hypofluorite (AcOF) with uracil, cytosine, and some N-1-substituted derivatives dissolved in either acetic acid or water has been investigated.Analysis by radio-h.p.l.c., using (18)f as a tracer, and by (1)H n.m.r. revealed that a substituent at N-1 of uracil has a remarkable effect on the stability of the intermediate 6-acetoxy-5-fluoro-5,6-dihydrouracils.In addition, it was found that these cytosine adducts rapidly deaminate in water yielding their corresponding uracil analogues.
Mechanism and Stereochemistry of the luorination of Uracil and Cytosine Using Fluorine and Acetyl Hypofluorite
Visser, Gerard W. M.,Boele, Saskia,Halteren, Bert W. v.,Knops, Gertrudis H. J. N.,Herscheid, Jacobus D. M.,et al.
, p. 1466 - 1471 (2007/10/02)
The products of the reaction of CH3COOF and F2 with uracil and cytosine dissolved in acetic acid and water were studied by using 18F as a tracer.Apart from 5-fluorouracil (2) and the 5,5-difluoro adducts 5a and 5b, the 1H NMR spectra of the crude reaction mixture showed the presence of two geometric isomers of both 5- fluoro-6-acetoxy-5,6-dihydrouracil (3a, 4a) and 5-fluoro-6-hydroxy-5,6-dihydrouracil (3b, 4b).In the fluorination of cytosine, corresponding products were observed with the exception of the acetoxy adducts.For both reagents and for both substrates a radical-cation mechanism is proposed.The observed conversions of the acetoxy adducts of uracil are explained by an acylimine (iii) as an intermediary.
