Synthesis and crystal structures of three Schiff bases derived from 3-formyl-acetyl-acetone and benzyl-, -butyl- and ()-methyl-benzyl-amine.

Treatment of 3-formyl-acetyl-acetone with the amines benzyl-amine, -butyl-amine and ()-methyl-benzyl-amine led to the formation of the corresponding Schiff bases 3-[(benzyl-amino)-methyl-idene]pentane-2,4-dione, CHNO (), 3-[(-butyl-amino)-methyl-idene]pentan-2,4-dione, CHNO () and 3-{[()-benz-yl(meth-yl)amino]-methyl-idene}pentane-2,4-dione, CHNO (). The mol-ecules of all three compounds exist as enamine tautomers that contain a nearly planar amino-methyl-ene-pentane-2,4-dione core with a strong intra-molecular N-H⋯O hydrogen bridge. The group attached to the enamine N atom has no significant influence on the bond lengths and angles of the amino-methyl-ene-pentane-2,4-dione core.

Synthesis and crystal structures of three Schiff bases derived from 3-formyl-acetyl-acetone and -, - and -amino-benzoic acid.

Treatment of 3-formyl-acetyl-acetone with the isomeric -, - and -amino-benzoic acids led to the formation of the corresponding Schiff bases, namely, 3-[(2-carb-oxy-phenyl-amino)-methyl-idene]pentane-2,4-dione, , 3-[(3-carb-oxy-phenyl-amino)-methyl-idene]pentane-2,4-dione, , and 3-[(4-carb-oxy-phenyl-amino)-methyl-idene]pentane-2,4-dione, , all CHNO, that contain a planar amino-methyl-ene-pentane-2,4-dione core with a strong intra-molecular N-H⋯O hydrogen bridge. The carb-oxy-phenyl groups attached to the nitro-gen atom are almost coplanar to the central mol-ecular fragment. Depending on the position of the carboxyl unit, different supra-molecular structures with hydrogen-bonding networks are formed in the three title structures.

Racemization-free synthesis of Nα-2-thiophenoyl-phenylalanine-2-morpholinoanilide enantiomers and their antimycobacterial activity.

Nα-2-thiophenoyl-D-phenylalanine-2-morpholinoanilide (MMV688845, IUPAC: N-(1-((2-morpholinophenyl)amino)-1-oxo-3-phenylpropan-2-yl)thiophene-2-carboxamide) from the Pathogen Box library (Medicines for Malaria Ventures, MMV) is a promising lead compound for antimycobacterial drug development. Two straightforward synthetic routes to the title compound starting from phenylalanine or its Boc-protected derivative are reported. Employing Boc-phenylalanine as starting material and the T3P and PyBOP amide coupling reagents enables racemization-free synthesis, avoiding the need for subsequent separation of the enantiomers.

Syntheses and crystal structures of three [(acac)(TMEDA)] complexes ( = Mn, Fe and Zn).

The complexes bis-(acetyl-acetonato-κ ,')(,,','-tetra-methyl-ethylenedi-amine-κ ,')manganese(II), [Mn(CHO)(CHN)], bis-(acetyl-acetonato-κ ,')(,,','-tetra-methyl-ethylenedi-amine-κ ,')iron(II), [Fe(CHO)(CHN)], and bis-(acetyl-acetonato-κ ,')(,,','-tetra-methyl-ethylenedi-amine-κ ,')zinc(II), [Zn(CHO)(CHN)], were synthesized from the reaction of the corresponding metal acetyl-acetonates [(acac)(HO)] with ,,','-tetra-methyl-ethylenedi-amine (TMEDA) in toluene. Each of the complexes displays a central metal atom which is nearly octa-hedrally surrounded by two chelating acac and one chelating TMEDA ligand, resulting in an NO coordination set. Despite the chemical similarity of the complex units, the packing patterns for compounds - are different and thus the crystal structures are not isotypic.