252048-06-9

Upstream product

• 211686-52-1 1-benzoyl-2(S)-isopropyl-6(S)-carboxy-perhydropyrimidin-4-one 
• 98-88-4 benzoyl chloride 
• 252048-05-8 1-benzoyl-(2S)-isopropyl-2,3-dihydro-4(1H)-1,3-pyrimidin-4-one 
• 74-88-4 methyl iodide 

Downstream Products

• 252047-91-9 (S)-1-benzoyl-2,3,5,6-tetrahydro-3-methyl-2-(1-methylethyl)pyrimidin-4(1H)-one 

Relevant academic research and scientific papers

Preparation of both enantiomers of β2-(3,4-dihydroxybenzyl) -β-alanine, higher homologues of Dopa

β2-(3,4-Dihydroxybenzyl)-β-alanine [β2-Homo-Dopa, 1] is a novel β-amino acid homologue of Dopa, the most successful therapeutic agent in the treatment of Parkinson's disease. Enantioenriched (R)-1 and (S)-1 were obtained via the diastereoselective alkylation of enantiopure pyrimidinone (R)- and (S)-3, chiral derivatives of β-alanine, with veratryl iodide. The major diastereomeric products (2S,5R)-4 and (2R,5S)-4 were hydrolyzed with 57% HBr, and the desired β-amino acids were purified by silica gel chromatography. Alternatively, enantioenriched (R)- and (S)-1 were prepared by means of the highly diastereoselective alkylation (3,4-dimethoxybenzyl iodide) of open-chain β-aminopropionic acid derivatives (R,R,S)-8 and (S,S,R)-8 containing the chiral auxiliary α-phenylethylamine. Finally, nearly enantiopure (R)- and (S)-1 were obtained by resolution of racemic N-benzyloxycarbonyl-2-(3,4- dibenzyloxybenzyl)-3-aminopropionic acid, rac-12, with (R)- or (S)-α-phenylethylamine, followed by catalytic hydrogenolysis.

X-ray crystallographic study of substituted perhydropyrimidinones. Extreme changes in ring conformation

X-ray crystal structures of 20 differently substituted perhydropyrimidin-4-ones are presented. Analysis of these data reveal a remarkable conformational sensitivity of a six-membered ring to substitution. Thus half-chair, envelope, boat, twist-boat, and intermediate conformations are found for the six-membered heterocycle, providing evidence for a relatively fiat conformational energy surface in this ring. Interpretation of the preferred conformations is advanced in terms of steric interactions among substituents and, in some cases, as the result of particular conformational (A1.3 strain, anomeric) effects.