59167-68-9Relevant academic research and scientific papers
Antithrombotic carboxylic acid amides
-
, (2008/06/13)
Carboxylic acid amides of formula having antithrombotic activity and a factor Xa-inhibiting activity. Exemplary are: 2-(5-amidino-2-hydroxy-phenyl)-N-[3-methyl-4-(2-tert-butoxycarbonylaminomethyl -benzimidazol-1-yl)-phenyl]-acetamide; 2-(5-amidino-2-hydro
Substituted Oxazoles: Synthesis via Lithio Intermediates
Whitney, Scott E.,Rickborn, Bruce
, p. 3058 - 3063 (2007/10/02)
Reactions of 2-α-, 2-, 4-, and 5-lithiooxazoles are used to prepare various substituted derivatives.Previously unrecognized time dependence for the reaction of a 2-lithiooxazole with benzaldhyde is described, and a rationale for this behavior is offered.Competitive reactions occur when the readily available 2,5-diphenyloxazole is treated with n-butyllithium.Deprotonation of the ortho position of the 2-phenyl group and addition of n-butyl to the 2-position of the oxazole compete with the desired 4-lithiation.The use of sec-butyllithium/catalytic lithium tetramethylpiperidide allows preferential formation of 4-lithio-2,5-diphenyloxazole.This intermediate has been converted to the 4-bromo, -methyl, -hydroxybenzyl, -benzoyl, and -trialkylsilyl derivatives.Lithiation of 2,4-diphenyloxazole and subsequent trimethylsilylation occur readily at the 5-position.Deprotonation of 2-alkyloxazoles occurs at the α-carbon in preference to ring sites.Further reaction of an α-phenyl-2-oxazolemethanol methoxymethyl ether with base and acetyl chloride leads to an acyloin derivative.Chromic acid oxidation is used to prepare both 2- and 4-benzoyloxazoles.The formation of an 2-ethoxyoxazole from 2-oxazolone vis Meerwein salt chemistry is described.
