- One-step synthesis of lumazine and xanthine: First co-crystal of lumazine and perchloric acid with a unique monohydrated hydronium ion (H 5O2+) mediated supramolecular assembly of the lumazine dimer
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A perchloric acid mediated one-step synthesis of lumazine derivatives from pterins and xanthine from guanine is reported. However, 2-pivaloylamino derivatives of pterins underwent simple hydrolysis of the pivaloylamino group generating free pterin compounds, but the 2-oxo derivatives, that is, the lumazine compounds, were not obtained. A novel supramolecular assembly is constructed by the unique hydrogen bonding of H5O2 + bridging two hydrogen-bonded dimers of lumazine to form the co-crystal 21 with aqueous perchloric acid. In contrast, N2-pivaloyl- 6-bromo-5-deazapterin was simply hydrolysed to form the protonated deazapterin 22, which forms a unique six-membered cyclic hydrogen-bonded structure leading to the generation of a polymeric supramolecular assembly. Wiley-VCH Verlag GmbH & Co. KGaA, 2007.
- Goswami, Shyamaprosad,Maity, Annada C.,Fun, Hoong-Kun
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p. 4056 - 4064
(2008/02/13)
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- A new, general and regioselective method for the synthesis of 2,6-disubstituted 4-aminopteridines
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A new synthetic method for the preparation of 2,6-disubstituted 4-aminopteridines is described. Treatment of a-substituted 4,5,6-triaminopyrimidines with α-ketoaldoximes in MeOH affords in a regioselective one-step reaction 2,6-disubstituted 4-aminopteridines in high yield.
- Taghavi-Moghadam, Shahriyar,Pfleiderer, Wolfgang
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p. 6835 - 6836
(2007/10/03)
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- PROTECTION AND DEPROTECTION OF FUSED 2-AMINO-4(3H)PYRIMIDONES: CONVERSION OF PTERINS AND 5-DEAZAPTERINS TO 2,4-DIAMINO DERIVATIVES
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5-Deazapterins and pterins are readily converted to their 4-deoxy-4-amino derivatives (a lactam-to-amidine conversion) by reaction with 4-chlorophenyl phosphorodichloridate and 1,2,4-triazole to give intermediate 4- derivatives, followed by reaction with aqueous ammonia.Some anomalous results obtained by application of the Mitsunobu reaction (normally a lactam-to-lactim ether conversion) to 5-deazapterins are detailed.
- Taylor, Edward C.,Otiv, S. R.,Durucasu, Inci
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p. 1883 - 1895
(2007/10/02)
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- Process for the production of methotrexate
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Process for the production of methotrexate, which is N[p-([(2,4-diamino-6-pteridyl)-methyl]-N10 -methylamino)-benzoyl]-L-glutamic acid. The process includes converting 1,1-dichloroacetone with 2,4,5,6-tetraaminopyrimidine in the presence of sodium bisulfite at a constant pH between 3.5 and 5 and at a temperature between 10° and 100° C. The resultant 2,4-diamino-6-methylpteridine is converted in a reaction medium with bromide. 0.3 to 1.0 ml of bromine is used per 1.0 g of the 2,4-diamino-6-methylpteridine. The 2,4-diamino-6-bromo methyl pteridine is converted with p-(N-methyl)-aminobenzoyl-L-glutamic acid or a salt thereof in a polar reaction medium into methoxtrexate.
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