Synthesis of a tricyclic tetraazatriacetic ligand for gadolinium(III) as potential contrast agent for MRI

Rapid Synthesis of New DNMT Inhibitors Derivatives of Procainamide

“…An activation-protection sequence was realised by reacting the primary amine of 1 with a small excess (1.25 equiv) of 2-nitrobenzenesulfonyl chloride (2-nosyl chloride) to give nosyl derivative 2. [26,27] Compound 3, an OH-derivatized l-RG108, was functionalised with a bromoalkyl linker of 6 or 12 atoms (4 and 5, respectively). An original one-pot reaction was developed: the coupling of 2 to 4 or 5 was performed in Williamson conditions, followed by double deprotection by thiophenol treatment and addition of water to afford 6 and 7.…”

Bimodal Probe for Magnetic Resonance Imaging and Photoacoustic Imaging Based on a PCTA‐Derived Gadolinium(III) Complex and ZW800–1

“…We previously reported the synthesis of PCTA(CO 2 t Bu) 3 ‐COOH,, , as a precursor of a bifunctional derivative of PCTA‐[12] bearing an additional carboxylic acid function anchored to the pyridine subunit that led to the corresponding Gd‐PCTA‐COOH chelate for application to the synthesis of targeted Gd‐based CA (Figure ). As previously discussed by us and other,, , the preferred synthetic route to PCTA(CO 2 t Bu) 3 ‐COOH was based on the assembly of two units bearing the final desired functionalities as it allows easier modulation of the nature and number of coordinating sites while avoiding post‐macrocyclization functionalization steps with boring selectivity control. Herein, we described optimized protocols to produce higher quantities of this key synthon that is precursor of a variety of PCTA‐based bifunctional chelators (BFC).…”

Nosyl (2-Nitrobenzenesulfonyl) Annulation Strategy toward Winding Vine-Shaped Bithiophenes

“…Removal of the solvent left a crude oil, which was subjected to purification by column chromatography on silica gel to afford 35 mg of 9a (85%) as a colorless oil. 1 H NMR (400 MHz, CDCl3) δ 2.67 (s, 4H), 3.75 (s, 4H), 6.99 (s, 2H), 13 C{ 1 H} NMR (100 MHz, CDCl3) δ 41. 7, 42.5, 113.9, 131.0, 131.5, 142.3, IR (ATR) 3367, 2923, 2850, 1723, 1586, 1451, 1127, 837 cm -1 , HRMS (DART+): calcd for C12H13 81 Br2N2S2 (M+H): 410.8846, Found: 410.8862.…”

“…Preparation of tetrabromobithiophene 6 Dinosylated diamine was prepared by the reaction of 1,2-ethylenediamine with 2 equivalents of 2-nitro-benzenesulfonyl chloride to give the nosylated ethylenediamine 7a. 8 We first examined the standard reaction conditions of the nosyl alkylation for the reaction of bithiophene bearing two bromomethyl groups 6 with 7a in the presence of potassium carbonate. This reaction was found to occur at 60 ºC in DMF as a solvent for 24 h to result in the consumption of bithiophene 6, as was confirmed by the analysis, leading to the cyclized product 8a in 99% yield after chromatographic purification.…”