Reaktion #543709

Reaktionsgleichung

29c

4-(6-methyl-thieno[2,3-d]isoxazol-3-yl)-piperidine-1-carboxylic acid tert-butyl ester

4-[1-(3-bromo-5-methyl-thiophen-2-yl)-1-hydroxyimino-methyl]-piperidine-1-carboxylic acid tert-butyl ester

→

4-(5-methyl-thieno[2,3-d]isoxazol-3-yl)-piperidine-1-carboxylic acid

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstige2) no partition between ethyl acetate and water
2. 2
   Extraktionaccompanied by subsequent extraction with ethyl acetate
3. 3
   SonstigePurification of the residue via flash column chromatography
4. 4
   workup.ADDITIONa mixture of ethyl acetate: n-heptane (1:4)
5. 5
   Sonstigeto yield a white solid

Vorschrift

Prepared essentially as in 29c except that 4-[1-(3-bromo-5-methyl-thiophen-2-yl)-1-hydroxyimino-methyl]-piperidine-1-carboxylic acid tert-butyl ester is used as the starting material. Two other differences are: 1) 0.05 equivalents of copper iodide is used, and 2) no partition between ethyl acetate and water accompanied by subsequent extraction with ethyl acetate is required. Purification of the residue via flash column chromatography uses a mixture of ethyl acetate: n-heptane (1:4) to yield a white solid. LC/MS (ESI), m/e 345 (MNa+), retention time 2.12 minutes. Condition II.

Quelle