5H-Pyrazolo[4,3-c]pyridine-5-carboxylic acid, 3-(2,3-dihydro-2-oxo-1H-imidazol-1-yl)-2-(4-fluoro-3,5-dimethylphenyl)-2,4,6,7-tetrahydro-4-methyl-, 1,1-dimethylethyl ester, (4S)-

China [CN]

Molecular Formula (Derived): C₂₅H₃₀FN₅O₃ (Based on the previous intermediate, the amino group is replaced with an imidazolinone ring, adding 4 C, 1 N, and 1 O, containing 1 F, 5 N, and 3 O)

Molecular Weight (Derived): 467.54 (Used for molar calculations and product quantification; the imidazolinone heterocycle increases the molecular weight by 81.07 compared to the preceding intermediate)

Core Application: A targeted drug intermediate containing a double heterocycle (pyrazolo[1,5-a]pyridine + imidazolinone) scaffold, mainly used in the synthesis of kinase inhibitors (such as JAK/FLT3 inhibitors), anti-inflammatory drugs, or metabolic drugs.

Key Structural Features: 1. Contains a pyrazolo[1,5-a]pyridine + imidazolinone double heterocycle (the core active scaffold of the drug, enhancing target selectivity); 2. Retains the (4S) chiral center, fluorinated aryl group, and tert-butyl ester protecting group; 3. The imidazolinone ring contains a carbonyl group (-C=O), increasing the molecule's hydrogen bonding capacity; 4. The parent nucleus is in a tetrahydro-reduced state, exhibiting excellent chemical stability.

Key Physicochemical Properties (Derived): 1. Appearance: White to off-white crystalline powder (typical morphology of double heterocycle ester intermediates); 2. Solubility: Slightly soluble in water, readily soluble in dichloromethane, tetrahydrofuran, N,N-dimethylformamide (DMF), sparingly soluble in petroleum ether (double heterocycle + fluorinated aryl group, moderate polarity); 3. Stability: Stable under sealed, dry storage at room temperature, avoid strong acids (tert-butyl ester deprotection), strong reducing agents (carbonyl group is easily reduced), and has good tolerance to oxidizing agents and weak bases; 4. Melting Point: Expected 180~200℃ (double heterocycle + chiral center, melting point is higher than the preceding intermediate).

Core Quality Indicators (Suggested): 1. Chiral Purity (ee value): ≥99% ((4S) configuration, core indicator, directly affecting the optical activity of downstream drugs); 2. Chemical Purity (HPLC): ≥98.5%; 3. Moisture Content: ≤0.5%; 4. Heterocyclic cyclization purity: ≥99% (to avoid uncyclized precursor impurities at the 3-position amino group)