32363-58-9Relevant academic research and scientific papers
Pteridines. Part CXIII. Protection of Pteridines
Yao, Qizheng,Pfleiderer, Wolfgang
, p. 1 - 12 (2007/10/03)
The low solubulity of pterins can drastically be improved by N2-acylation or formation of the N2-[(dimethylamino)methylene] derivatives. Both types of compounds can be alkylated under Mitsunobu conditions to form from N2-acylpterins (see 2 and 3) and their derivatives (see 5, 6, 8, 9, 11, 13, 15, and 17) selectively the O4-alkyl derivatives 22-31, whereas the electron-donating [(dimethylamino)methyleneamino] function in 46-51 gives, in a selective reaction, the N(3)-substitution (->52-61). N2,N2-Dimethylpterins and 18 and 19 and N2-methylpterins 20 and 21 direct alkylation also to the O4-position (->32-35, 38 and 39). Deacylation can be achieved under very mild conditions by solvolysis with MeOH (22->40, 26->41), and displacement of the O4-[2-(4-nitrophenyl)ethyl] group proceeds with ammonia at room temperature to the corresponding pteridin-2,4-diamine 42-45. Cleavage of the N2-[(dimethylamino)methylene] group works well with ammonia (->62-67). The advantage of applying the 2-(4-nitrophenyl)ethyl (npe) group as blocking group is seen in its selective removal by 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) under aprotic conditions without harming the other substituents.
Pteridines, LXIX. Synthesis and Reactivity of 2,4-Diamino-6-(hydroxymethyl)pteridine
Boyle, Peter H.,Pfleiderer, Wolfgang
, p. 1514 - 1523 (2007/10/02)
Condensation of 2,4,5,6-tetraaminopyridine (2) with 1,3-dihydroxyacetone in the presence of gaseous oxygen, rather than air, resulted in 2,4-diamino-6-(hydroxymethyl)pteridine (3) virtually uncontaminated with 2,4-diamino-6-methylpteridine (4).Acetylation of 3 led to 6-acetoxymethyl-2,4-bis(acetylamino)pteridine (5) which turned out to be very labile forming various di- and monoacetyl derivatives (6, 7, 9, 10) on mild hydrolytic conditions.Their structures are proven by physical-chemical means.Silylation of 3 to the tris(trimethylsilyl) derivative 11 followed by treatment with 1-O-acetyl-2,3,5-tri-O-benzoyl-β-D-ribofuranose (12) and 1,2,3,4,6-penta-O-acetyl-β-D-glucopyranose (15), respectively, in the presence of boron trifluoride,led to selective formation of the corresponding acylated 2,4-diamino-6-pteridinyl O-glycosides 13 and 15, respectively.Deacylations of these afforded the free O-glycosides 14 and 17 which have been characterized by UV- and NMR spectra as well as pKa measurements.
