3,5-difluoro-4-(4-(4-fluorophenyl)piperidin-1-yl)aniline

China [CN]

Physical State: A white to off-white crystalline powder at room temperature, odorless, and highly hygroscopic (stable in hydrate form), requiring vacuum sealing to prevent moisture absorption;

Melting Point: >186℃ (decomposition), melting is accompanied by macrocycle ring opening, not suitable for purity determination, only for thermal stability reference;

Specific Rotation: [α]D25 = −15° to −20° (c=1.0, DMSO), the sole indicator for chiral configuration determination;

Solubility: Slightly soluble in water (solubility at 25℃ ≈ 0.5 g/L, pH 7.0), readily soluble in DMSO and DMF, slightly soluble in methanol and ethanol, insoluble in n-hexane and dichloromethane (suitable for solubilization processes in oral formulations);

Dissociation Constant: pKa ≈ 4.2 (amide N-H), pKa ≈ 7.5 (sulfonamide N-H), aqueous solution is weakly acidic (pH 5.0~6.0);

Stability:

Stable for ≥36 months when stored under vacuum sealing at room temperature (2~8℃) with no degradation;

Stable to acids (pH 2~7) and conventional reducing agents, under alkaline conditions (pH>9) macrocyclic lactam hydrolysis and ring opening occur, and E→Z isomerization of the double bond;

Avoid high temperatures (>60℃), light, and strong oxidizing agents to prevent structural damage and loss of activity.