42457-28-3

Upstream product

• 683-58-9 acetohydroximoyl chloride 
• 1608-03-3 (E)-but-1-en-3-yn-1-ylbenzene 
• 100-52-7 benzaldehyde 
• 30856-31-6 diethyl [(3-methyl-1,2-oxazol-5-yl)methyl]phosphonate 
• 75624-65-6 4-Methoxy-5-(triphenylphosphoranyliden)-3-penten-2-on 
• 188557-88-2 (1E,4Z)-5-(isopropylamino)-1-phenylhexa-1,4-dien-3-one 
• 300-87-8 3,5-dimethyl-1,2-oxazole 
• 75624-75-8 (3-Methyl-5-isoxazolylmethyl)triphenylphosphonium-chlorid 

Relevant academic research and scientific papers

Preparation, alkylation, and olefination reaction of 5-phosphonomethyl- 3-methylisoxazole

5-Diethylphosphonomethyl-3-methylisoxazole (1) was synthesized by two methods, 1) cycloaddition of nitrile oxide and 2) nucleophilic reaction of the 3,5-dimethylisoxazole anion. This phosphonoisoxazole 1 was alkylated and olefinated by reaction of its ani

An efficient, scaleable procedure for the conversion of esters to isoxazoles

A concise, regiocontrolled route to isoxazoles, based on the condensation of an ester with a metallated imine, has been developed. The intermediate vinylogous amides react smoothly with hydroxylamine to provide, after dehydration, substituted isoxazoles. The method has been used for the multi-kilo scale preparation of ABT-418, a novel cholinergic channel activator.

Reactions with Organophosphorus Compounds, XLVI. Reactivity Umpolung of 1,3-Dioxo Compounds through Introduction of a Triphenylphosphonio Group. - Regioselective Syntheses of Isoxazoles and Pyrazoles from (2,4-Dioxoalkyl)triphenylphosphonium Salts

Phosphonium salts 2 and 6, upon deprotonation with BuLi and subsequent reaction with acyl halides, yield the γ-acyl derivatives 3 and 7, respectively, which on treatment with hydrochloric acid afford the corresponding (dioxoalkyl)phosphonium salts 4 and 8.Isoxazole derivatives 9 and 10 are formed regioselectivly from 4 and 8 with NH2OH*HCl, while with R-NH-NH2*HCl (R = H or C6H5) the pyrazole-containing phosphonium salts 14 and 15 are obtained in an analogous reaction.In each case the direction of cyclisation is different to the reactions of the corresponding non-phosphorus substituted 1,3-dioxo compounds.On treatment with aqueous NaOH 9 and 10 are cleaved to triphenylphosphane oxide and isoxazoles 11 and 12, while 14 and 15 yield the pyrazoles 16 and 17.Wittig reaction of 9a or 14a with aldehydes or ketones leads to the isoxazole olefins 13 or the pyrazole olefins 18, respectively.