Studies on Chemotherapeutics. XXXII

Synthesis and structure of isocytosine ternary copper(II) complexes †

“…12,20 This is consistent with the structure found in the crystal, although a stronger axial water interaction seems to occur in solution. The π-π* transition bands corresponding to the pyrimidine ring of the isocytosine [263 (sh), ε = 3.7 × 10 3 ; 284 nm, ε = 4.49 × 10 3 dm 3 mol Ϫ1 cm Ϫ1 ] exhibit some changes in intensity and slight shifts to higher 2)᎐N(3) C(4)᎐O(4) O( 7)᎐C( 8) C( 8)᎐O( 8) C( 9)᎐N( 10) N( 10)᎐C( 11) C( 11)᎐O( 11) N( 10)᎐Cu᎐N( 3) N( 10)᎐Cu᎐O( 7) N( 3)᎐Cu᎐O( 7) N( 10)᎐Cu᎐N( 13) N( 3)᎐Cu᎐N( 13) O( 7)᎐Cu᎐N( 13) C( 2)᎐N(3)᎐Cu C(4)᎐N(3)᎐Cu C( 8)᎐O (7)᎐Cu C( 11)᎐N( 10)᎐C( 9) C( 11)᎐N (10) (14) energies on complexation (261, ε = 6.18 × 10 3 ; 283 nm, ε = 6.10 × 10 3 dm 3 mol Ϫ1 cm Ϫ1 ). The corresponding band of methylisocytosine (266 nm, ε = 5.10 × 10 3 dm 3 mol Ϫ1 cm Ϫ1 ) is displaced to higher energies (262 nm, ε = 8.9 × 10 3 dm 3 mol Ϫ1 cm Ϫ1 ) increasing its relative intensity.…”

“…The ternary complexes (glycylglycinato)(isocytosine)copper() dihydrate 1 and (glycylglycinato)(6-methylisocytosine)copper() monohydrate 2 have been prepared and characterised by X-ray diffraction, electrochemistry and optical, ESR and IR spectroscopy. The two compounds are slightly distorted square planar, with the four co-ordination sites occupied by the tridentate glycylglycine dianion [O (7), N (13) and N (10)] and N(3) of the pyrimidine base. An additional weak axial interaction exists between an oxygen of a water molecule O(W1) and the copper atom [Cu ؒ ؒ ؒ O(W1) distances 2.74 and 2.70 Å respectively].…”

“…2-hydrazino-4-hydroxy-6-methylpyrimidine has been reported to be active against Mycobacterium tuberculosis (human type H 2 -strain). 7 In this work we report on the preparation, spectroscopic characterisation and crystal and molecular structures of the ternary complexes (glycylglycinato…”

Synthesis and Anti-HBV Activity of Isocytosine Derivatives linked to 5-position of methyl β-D-ribofuranoside

“…15 Tosylation of 5 using p-toluenesulfonyl chloride in pyridine afforded 6 in 90% yield. Displacement of the tosyloxy group with potassium phthalimide and sodium iodide in DMF afforded methyl 2,3-O-isopropylidene-5-O-phthalimidoethyl-β-d-ribofuranoside (7) in 93% yield. Phthalimido group was deprotected with hydrazine hydrate in methanol at reflux temperature to afford the corresponding amino derivative 8 in 89% yield.…”

“…5 Isocytosine (2-amino-4-pyrimidinone) designates the pyrimidine part of guanine, and even though it is not involved directly as a carrier of the genetic code, it is of biological significance and its medical applications are numerous. 6 A variety of 2-amino-4-pyrimidinones display anticancer, antiviral, antibacterial properties, 7 or are valuable agrochemicals. 8 Specifically, platinum group metal complexes of isocytosine and derivatives attract considerable attention because of their antitumor activity.…”