2.4- Diamino-6-hydroxy-pyrimidin

The preparation of 9-niethyl and 9-butyl-2-hydroxy-8,9-dihydro-7H-purine-8-thione (XXVa Table 7) is somewhat unusual. Brown [45) has obtained these compounds from carbon disulfide and respectively f-methyl and 1 -butyl-5,6-diamino-1,2-dihydropyrimidin-2-one (XXIVa.). Evidently a shift of the alkyl group from the 3-N to the 9 N atom must occur during the ring closure. The structure of these two purines has been confirmed by their independent synthesis from 4-methylamino and 4-butylamino-5-amino-2-hydroxy pyrimidine. 

Pyrimido[5,4-d]pyrimidine, 6,8-diamino-4-hydroxy-2-phenyl-synthesis, 3, 364... 

Balzarini J, Schols D, Van Laethem K, De Clercq E, Hockovd D, Masojidkova M, Holy A (2007) Pronounced in vitro and in vivo antiretroviral activity of 5-substituted 2,4-diamino-6-[2-(phosphonomethoxy)ethoxy]pyrimidines, J Antimicrob Chemother 59 80-86 Beadle JR, Wan WB, Ciesla SL, Keith KA, Hartline C, Kern ER, Hostetler KY (2006) Synthesis and antiviral evaluation of alkoxyalkyl derivatives of 9-(S)-(3-hydroxy-2-phosphonomethoxypropyl)adenine against cytomegalovirus and orthopoxviruses, J Med Chem 49 2010-2015... 

Ferrarini et al. studied the reaction of 2,6-diamino- and 2-amino-6-acetamidopyridine with different jS-oxo esters in polyphosphoric acid at 80°C (90JHC881). Generally, complex reaction mixtures that contained different bi- and tricyclic products were obtained (see Scheme 7 and Table IX). The products were separated by flash chromatography. In the case of 2-amino-6-acetamidopyridine, the 2,6-diacetamidopyridine 97 was the main product. This compound 97 was also obtained by transamidation in good yield when 2-amino-6-acetamidopyridine was heated in polyphosphoric acid at 80°C. 2-Hydroxy-1,8-naphthyridines 98 were formed in a Conrad-Limpach-type cyclocondensation of 2-aminopyridines and /3-keto ester, while 4-hydroxy-1,8-naphthyridines 99 were probably formed by a ring transformation of 4//-pyrido[l,2-a]pyrimidin-4-ones 100 obtained by the cyclocondensation of 2-aminopyridines and a /3-keto ester. The cyclocondensation of 7-amino-4-hydroxy-l,8-naphthyridine 99 (R = H) and a... 

Diamino-6-hydroxypyrimidine condenses with nitromalonaldehyde in presence of alkali to give 2-amino-4-hydroxy-6-nitropyrido[2,3-d]pyrimi-dine (100) (75%).92 In a similar reaction 2,4-dioxo-l-hydroxy-6-nitro-lf/,3//-pyrido[2,3-d]pyrimidine is formed (101) [Eq. (32)].93... 

In addition to the pyrazino[2,3-d]pyrimidin-7-yl C-nucleoside 609 and its homo analog 614, which were obtained by the reaction of 5,6-diamino-l,3-dimethyluracil with the 6-hydroxy-6-/8-D-ribofuranosyl-2/7-pyran-3(6//)-one derivative 606 (Section XI,B Scheme 162), the pyrrolo-pyrazino-pyrimidine C-nucleoside 680 was produced in 30% yield according to the mechanism outlined in Scheme 175 (89JOC3927). 

Uber die Cyclisierung von 3(5)-(3-Oxo-alkanoylamino)-lH-pyrazolen werden die 5-Hydroxy-Isomeren erhalten2171. Aus 3(5)-Amino-5(3)-hydroxy-l H-pyrazol und 3-Oxo-butansaure-ethyl-ester ist 2,7-Dihydroxy-5-methyl-(pyrazolo[l,5-a]pyrimidin (74% Schmp. > 300°) zugang-lich2174. 3,5-Diamino-lH-pyrazole kondensieren unter analogen Bedingungen zu 2-Amino-7-hydroxy-5-methyl-2165 2175 ... 

Zur Cyclisierung von 2,5-Diamino-4-hydroxy-6-mercapto-pyrimidin mit Brom-cyan s. Lit... 

SOME PYRIMIDINES OF BIOLOGICAL AND MEDICINAL INTEREST—PART III A number of 4,6-disubstituted 5-nitropyrimidines have been claimed to be useful as fungicides [471]. A 100 per cent control of typical fungi was attained with a 0-1 per cent concentration of 5-nitropyrimidines having the following substituents 4,6-dichloro-, 4-chloro-6-amino-, 4,6-diamino, and 4,6-di-hydroxy-. The 4,6-dichloro derivative (XCII) is the best. All compounds maintained some activity at 0-001 per cent concentrations. 

Other pyrimidine derivatives sulfonated in the 5-position by treatment with chlorosulfonic acid at the temperatures shown in brackets included 2-chloro- and 2,4-dichloro 2-amino, by boiling chlorosulfonic acid (10 equivalents, 8 hours) 4-methyl-2-amino (110°C) 6-methyl-2,4-diMmno (110°C) 4-hydroxy-2-amino (110°C) 6-methyl-4-hydroxy-2-amino (110°C) 4-hydroxy-2,6-diamino (100 °C) 2-hydroxy-4,6-diamino (100 °C) 2-methylthio-4,6-diamino (100 °C) 2-methyl-4-hydroxy-6-amino (100°C) 2-hydroxy (110°C) " 2-hy-droxy-4-amino (110°C) 6-methyl-2-hydroxy-4-amino (110 C) 6-amino-2,4-dihydroxy (90°C) 4-amino-6-hydroxy (100 C) 2,4-diamino-6-chloro, by boiling chlorosulfonic acid (eight equivalents, 1 hour). ... 

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