1500113-89-2

Upstream product

• 177948-39-9 (R)-tert-butyl 4-((2-hydroxy-1-phenylethyl)amino)piperidine-1-carboxylate 
• 56613-80-0 D-2-phenylglycinol 
• 79099-07-3 N-tert-butyloxycarbonylpiperidin-4-one 
• 125568-73-2 2,4-difluoro-5-aminobenzoic acid methyl ester 

Downstream Products

• 1500113-90-5 (R)-tert-butyl 4-(3-(2,4-difluoro-5-(methoxycarbonyl)phenyl)-2-oxo-5-phenylimidazolidin-1-yl)piperidine-1-carboxylate 
• 1500113-91-6 (R,Z)-tert-butyl 4-(2-((2,4-difluoro-5-(methoxycarbonyl)phenyl)imino)-4-phenyloxazolidin-3-yl)piperidine-1-carboxylate 
• 1500113-92-7 (R)-5-(3-(1-(tert-butoxycarbonyl)piperidin-4-yl)-2-oxo-4-phenylimidazolidin-1-yl)-2,4-difluorobenzoic acid 

Relevant academic research and scientific papers

Alkali carbonate effects on N-(2-hydroxyethyl)urea cyclization: Application to a 2-imidazolidinone scale-up

An imidazolidinone intermediate (3) used in the synthesis of novel HIV-entry inhibitors was prepared on multihundred gram scales in four steps and 40% overall yield. The penultimate step in the synthesis involved regioselective N-cyclization of N-(2-hydroxylethyl)urea (11) by in situ activation of the terminal hydroxyl group with p-TsCl in the presence of base. The ratio of N-cyclized to O-cyclized products followed a group IA periodic trend relative to the alkali carbonate base employed. The use of Cs2CO3 as base effected the desired N-cyclization with a high degree of regiocontrol (>98%).