Breathing control modulating compounds, and methods of making and using same

A compound that is 1-(2,6-Bis-methylamino-8-propylamino-pyrimido[5,4-d]pyrimidin-4-yl amino)-2-methyl-propan-2-ol (31) or at least one crystalline salt selected from the group consisting of:

• (xiii) Crystalline hydrochloride salt (31a), with a XRPD spectrum as per FIG. 3A;
• XRPD peaks as per FIG. 3B;
• and/or DSC spectrum as per FIG. 3C;
• (xiv) Crystalline bis-hydrochloride salt (31b), with a XRPD spectrum as per FIG. 4A;
• XRPD peaks as per FIG. 4B;
• and/or DSC spectrum as per FIG. 4C;
• (xv) Crystalline hydrogen malonate salt (31c), with a XRPD spectrum as per FIG. 5A;
• XRPD peaks as per FIG. 5B;
• and/or DSC spectrum as per FIG. 5C;
• (xvi) Crystalline hydrogen maleinate salt Form Male-A (31d-1), with a XRPD spectrum as per FIG. 6A;
• XRPD peaks as per FIG. 6B;
• and/or DSC spectrum as per FIG. 6C;
• (xvii) Crystalline hydrogen maleinate salt Form Male-B (31d-2), with a XRPD spectrum as per FIG. 7A;
• XRPD peaks as per FIG. 7B;
• and/or DSC spectrum as per FIG. 7C;
• (xviii) Crystalline hydrogen fumarate salt (31e), with a XRPD spectrum as per FIG. 8A;
• XRPD peaks as per FIG. 8B;
• and/or DSC spectrum as per FIG. 8C;
• (xix) Crystalline hydrogen L(+)tartrate salt (31f), with a XRPD spectrum as per FIG. 9A;
• XRPD peaks as per FIG. 9B;
• DSC spectrum as per FIG. 9C;
• (xx) Crystalline D,L-mandelate salt (31g), with a XRPD spectrum as per FIG. 10A;
• XRPD peaks as per FIG. 10B;
• and/or DSC spectrum as per FIG. 10C;
• (xxi) Crystalline tosylate salt form Tos-A (31h-1), with a XRPD spectrum as per FIG. 11A;
• XRPD peaks as per FIG. 11B;
• and/or DSC spectrum as per FIG. 11C;
• (xxii) Crystalline tosylate salt form Tos-B (31h-2), with a XRPD spectrum as per FIG. 12A;
• XRPD peaks as per FIG. 12B;
• and/or DSC spectrum as per FIG. 12C;
• (xxiii) Crystalline mesylate salt (31i), with a XRPD spectrum as per FIG. 13A;
• XRPD peaks as per FIG. 13B;
• and/or DSC spectrum as per FIG. 13C;
• (xxiv) Crystalline saccharinate salt (31j), with a XRPD spectrum as per FIG. 14A;
• XRPD peaks as per FIG. 14B;
• and/or DSC spectrum as per FIG. 14C;
• and any mixtures thereof.