"Sigma tests adenine in 1 M HCl at 20 mg/mL, obtaining a clear colorless solution. (Note that the hydrochloride salt is directly water-soluble.)
Adenine is soluble in at 1 part to ~2000 parts cold water, 1 part in 40 of boiling water; slightly soluble in hot alcohol; insoluble in chloroform, ether; soluble in hot NH4OH" from https://www.sigmaaldrich.com/content/dam/sigma-aldrich/docs/Sigma/Product_Information_Sheet/a8626pis.pdf with Merck Index, 12th ed., #150 (1996).
5. Martindale: The Extra Pharmacopoeia, 30th ed.(Pharmaceutical Press, 1993), p. 1331.
So is not very soluable in these solvents. Maybe a little bit in hot methanol but not in CHCl3. But i cant find any exact numbers in literature for this compound. It should be easier for you if you just try to solve adenine. It isnt an expensive compound. Try to solve 10mg in small vessels up to some mL of the solvent and hot solvent and you will get your answer if it is that important. Otherwise just google "adenine solubility" and you will find the same answers than me.
easily SOLUBLE IN ACETIC ACID AS WELL AS FORMIC ACID.
Easily soluble in acetic acid; formic acid (50 mg/mL - clear, colorless solution), 0.5 M Hydrochloric acid (20 mg/mL - clear to slightly hazy, colorless to faint yellow solution). Soluble in water (1 g/2000 mL at 25 °C; 1 g/40 mL boiling water); slightly soluble in ethanol.