Synthesis and evaluation of 2-(2-fluoro-4-hydroxymethyl-5-methoxy-phenoxy)acetic acid as a linker in solid-phase synthesis monitored by gel-phase19F NMR spectroscopy

Crystal structure and mol-ecular docking study of diethyl 2,2'-({[(1E,1'E)-(hydrazine-1,2-diyl-idene)bis-(methanylyl-idene)]bis-(4,1-phenyl-ene)}bis-(-oxy))di-acetate

The title Schiff base, C22H24N2O6, adopts an E configuration. The mol-ecule is planar, the mean planes of the phenyl ring system (r.m.s deviation = 0.0059 Å) forms a dihedral angle of 0.96 (4)° with the mean plane of the phenyl ring moiety (r.m.s deviation = 0.0076 Å). In the crystal, mol-ecules are linked by weak inter-molecular C-H⋯O and C-H⋯N hydrogen bonds into chains extending along the c-axis and b-axis directions, respectively. A mol-ecular docking study between the title mol-ecule and 5-HT2C, which is a G protein receptor and ligand-gated ion channels found in nervous systems (PDB ID: 6BQH) was executed. The experiment shows that it is a good potential agent because of its affinity and ability to stick to the active sites of the receptor.

Parallel solid-phase synthesis and high-throughput 1H NMR evaluation of a 96-member 1,2,4-trisubstituted-pyrimidin-6-one-5-carboxylic acid library

A solid-phase organic synthesis method has been developed for the preparation of trisubstituted pyrimidin-6-one carboxylic acids 12, which allows elaboration to a 3-dimensional combinatorial library. Three substituents are introduced by initial Knoevenagel condensation of an aldehyde and malonate ester resin 7 to give resin bound 1. Cyclization of 1 with an N-substituted amidine 10, oxidation, and cleavage afforded pyrimidinone 12. The initial solid-phase reaction sequence was followed by gel-phase (19)FNMR and direct-cleavage (1)H NMR of intermediate resins to determine the optimal conditions. The scope of the method for library production was determined by investigation of a 3 x 4 pilot library of twelve compounds. Cyclocondensation of N-methylamidines and 7 followed by CAN oxidation gave mixtures of the resin bound pyrimidin-6-one 11 and the regioisomeric pyrimidin-4-one 15, which after cleavage from the resin afforded a nearly 1:1 mixture of pyrimidin-6-one and pyrimidin-4-one carboxylic acids 12 and 16, respectively. The regiochemical assignment was confirmed by ROESY1D and gHMBC NMR experiments. A library was prepared using 8 aldehydes, 3 nitriles, and 4 amines to give a full combinatorial set of 96 pyrimidinones 12. Confirmation of structural identity and purity was carried out by LCMS using coupled ELS detection and by high-throughput flow (1)H NMR.