RESUMO
In the title compound, C12H12N2O4, the di-hydro-pyrrole ring is almost planar (r.m.s. deviation = 0.0049â Å) and is nearly coplanar with the adjacent C2O2 residue [dihedral angle = 4.56â (9)°], which links to the 4-nitro-benzene substituent [dihedral angle = 4.58â (8)°]. The mol-ecule is concave, with the outer rings lying to the same side of the central C2O2 residue and being inclined to each other [dihedral angle = 8.30â (7)°]. In the crystal, supra-molecular layers parallel to (10-5) are sustained by nitro-benzene-C-Hâ¯O(carbon-yl) and pyrrole-C-Hâ¯O(nitro) inter-actions. The layers are connected into a three-dimensional architecture by π(pyrrole)-π(nitro-benzene) stacking [inter-centroid separation = 3.7414â (10)â Å] and nitro-Oâ¯π(pyrrole) inter-actions.
RESUMO
The title compound, C14H17NO4, features an epoxide-O atom fused to a pyrrolidyl ring, the latter having an envelope conformation with the N atom being the flap. The 4-meth-oxy-phenyl group is orthogonal to [dihedral angle = 85.02â (6)°] and lies to the opposite side of the five-membered ring to the epoxide O atom, while the N-bound ethyl ester group (r.m.s. deviation of the five fitted atoms = 0.0187â Å) is twisted with respect to the ring [dihedral angle = 17.23â (9)°]. The most prominent inter-actions in the crystal are of the type methine-C-Hâ¯O(carbon-yl) and these lead to the formation of linear supra-molecular chains along the c axis; weak benzene-C-Hâ¯O(epoxide) and methine-C-Hâ¯O(meth-oxy) inter-actions connect these into a three-dimensional architecture. The analysis of the Hirshfeld surface confirms the presence of C-Hâ¯O inter-actions in the crystal, but also the dominance of Hâ¯H dispersion contacts.
RESUMO
We report herein a new, practical, and economic synthesis of the phosphodiesterase inhibitor Rolipram on a multigram scale as well as the synthesis of new 4-aryl pyrrolidones and beta-aryl-gamma-amino butyric acids (GABA derivatives) employing an efficient Heck-Matsuda arylation of 3-pyrroline with aryldiazonium tetrafluoroborates. Racemic Rolipram was resolved into its enantiomers using chiral simulated moving bed chromatography having the low-cost microcrystalline cellulose triacetate as a chiral stationary phase.
Assuntos
Boratos/química , Compostos de Flúor/química , Inibidores de Fosfodiesterase/síntese química , Prolina/análogos & derivados , Pirrolidinonas/síntese química , Rolipram/síntese química , Ácido gama-Aminobutírico/análogos & derivados , Ácido gama-Aminobutírico/síntese química , Boratos/metabolismo , Cromatografia por Troca Iônica/métodos , Compostos de Diazônio/química , Compostos de Diazônio/metabolismo , Compostos de Flúor/metabolismo , Prolina/química , Pirrolidinonas/química , EstereoisomerismoRESUMO
[reaction: see text] The diastereoselectivity of the Heck arylation of several chiral, nonracemic, five-membered endocyclic enecarbamates with aryldiazonium tetrafluoroborates was evaluated. The cis selectivity observed for some enecarbamates bearing coordinating groups was explored in the concise synthesis of the (2S,5R)-(+)-phenylproline methyl ester, a scaffold for the nonpeptide cholecystokinin antagonist (+)-RP 66803, and in the synthesis of Schramm's potent antiprotozoan C-azanucleoside.