title: The photochemistry of 2-alkoxycytosines in phosphate buffer and its link to cytosine photochemistry in alcoholic solution.
abstract: The reactions occurring when 2-methoxycytosine (4-amino-2-methoxypyrimidine) (I) and 2-ethoxycytosine (II) are irradiated in aqueous phosphate buffer at pH 7 have been studied. We have verified the previous results of Moore [Can. J. Chem. 41, 1937-1950 (1963)], who studied I and indicated that the product isolatable in greatest yield is N-carbomethoxy-3-hydroxyacrylamidine (IIIa). Similarly, we have found that the product of highest yield, isolated after irradiation of II, is N-carboethoxy-3-hydroxyacrylamidine (IIIb). Evidence is presented indicating that these are secondary products, being produced through hydrolysis of the corresponding N-carboalkoxy-3-aminoacrylamidines. Spectroscopic data are given for N-carboisopropoxy-3-hydroxyacrylamidine (IIIc), as well as the N-carbomethoxy, N-carboethoxy and N-carboisopropoxy derivatives of 3-hydroxy-2-methylacrylamidine. These four compounds were obtained through hydrolysis of the corresponding N-carboalkoxy derivatives of 3-aminoacrylamidine or 3-amino-2-methylacrylamidine, isolated from the photoreaction of cytosine or 5-methylcytosine with the appropriate alcohol.
authors.forename: A A
authors.initials: AA
authors.lastname: Shaw
authors.forename: M D
authors.initials: MD
authors.lastname: Shetlar
mesh_terms: D000438:Alcohols; D003596:Cytosine / Q000031:analogs & derivatives* / Q000528:radiation effects*; D010782:Photolysis; D012996:Solutions; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship; D014466:Ultraviolet Rays
chemical_list: D000438:Alcohols; D012996:Solutions; D003596:Cytosine