Pteridines, 2-amino-, basicity

Pseudooxazolones, see 3-oxazolin-6-ones Pteridines, 2-amino-, basicity of, 27 2-amino-, hydration of, 12,13,27-28 2-amino-, polarographic reduction of, 51... 

Pteridine, 2-amino-4-benzyIamino-6,7-diphenyl-synthesis, 3, 294 Pteridine, 2-amino-6,7-diethyl-hydrolysis, 3, 294 Pteridine, 4-amino-6,7-diethyl-hydrolysis, 3, 294 Pteridine, 7-amino-5,6-dihydro-synthesis, 3, 314 Pteridine, 2-amino-4,7-dimethyl-basicity, 3, 267... 

Pteridine, 2-amino-4,6,7-trimethyl-basicity, 3, 267 Pteridine, 2,2 -anhydro-nucleosides, structure, 3, 283 Pteridine, 2,5 -anhydro-nucleosides structure, 3, 283 Pteridine, 6-aryl-synthesis, 3, 316 Pteridine, 7-aryl-synthesis, 3, 314... 

Xanthopterin monohydrate (2-amino-4,6-dihydroxypteridine, 2-amino-pteridin-4,6(lff,5ff)-dione) [5979-01-1 (H2O), 119-48-8 (anhydr)] M 197.2, m <300", pK, 1.6 (basic), pKj 6.59 (acidic), PK3 9.31 (acidic)(anhydrous species), and pKj 1.6 (basic), pK2 8.65 (acidic), PK3 9.99 (acidic)(7,8-hydrated species). Purification as for isoxanthopterin. Crystd by acidifying an ammoniacal soln, and collecting by centrifugation followed by washing with EtOH, ether and drying at 100° in vacuo. Paper chromatography Rp 0.15 ( -PrOH, 1% aq NH3, 2 1), 0.36 ( -BuOH,AcOH, H2O, 4 1 1) and 0.47 (3% aq NH3). [Inoue and Perrin J Chem Soc 260 7962 Inoue Tetrahedron 20 243 I964 see also Blakley Biochemistry of Folic Acid and Related Pteridines North Holland Publ Co, Amsterdam 1969.]... 

Pterin (2-amino-4-hydroxypteridine, which occurs in the lactam form 8) and lumazin (2,4-dihy-droxypteridine, which exists as the l,2,3,4-tetrahydropteridine-2,4-dione structure 9) are the basic structures of the naturally occurring pteridine derivatives ... 

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