Structural chemistry of N(7)-substituted purines: the crystal and molecular structure of 7-methylxanthine hydrochloride monohydrate

Structure of 3-methylxanthine

“…Atomic coordinates of the non-H atoms are given in Table 1. * The bond lengths and angles (Table 2) are similar to those obtained for 7-methylxanthine hydrochloride monohydrate (Kistenmacher & Sorrell, 1975), the most significant differences being accounted for by the different exocyclic substituents on N(3), N(7) and N(9). Each molecule is involved in four hydrogen bonds, two of which are to molecules related by the inversion centre.…”

Reaction of coordinated purines. Facile, high yield synthetic route to N(7)-alkylated xanthines and hypoxanthines. Structure of [bis(dimethylglyoximato)(xanthinato)(tri-n-butylphosphine)cobalt(III)] and the trans influence in cobalt(III) chemistry

“…The X-ray results confirmed that the reaction product was indeed 7-methylxanthine. 24 We believe then that the combined spectroscopic and X-ray results support previous structural assignments which have been based on specific synthetic procedures. Furthermore, these results indicate that the major product, very small amounts of other isomers being undetectable, of alkylation of the xanthinato and hypoxanthinato complexes is the N(7) isomer.…”

The crystal structure and conformational analysis of acetylcarnitine hydrochloride monohydrate

“…Bond distances and angles involving H atoms are reported in Table 6. The average length of the 17 C--H bonds is 0.97/~; that of the two O-H bonds in the water molecule, 0.80/~, agrees with the values found in arginine hydrochloride monohydrate, 0.83 /~, (Dow, Jensen, Mazumdar, Srinivasan & Ramachandran, 1970), and in 7-methylxanthine hydrochloride monohydrate, 0.76/~ (Kistenmacher & Sorrell, 1975). The most convenient parameters for the description of the molecular conformation are the torsion angles reported in Table 7, where the values found in ACC and CAR are compared with the corresponding ones in other fl-methyl derivatives of choline.…”