N-methyl-N-(tert-butoxycarbonyl)-4-penten-2-amine → (4E)-N-methyl-5-(5-oxazolo[5,4-b]pyridinyl)-4-penten-2-amine
반응식
Br[C:2]1[N:7]=[C:6]2[O:8][CH:9]=[N:10][C:5]2=[CH:4][CH:3]=1.BrC1C=C2OC=NC2=NC=1.[CH3:21][N:22](C(OC(C)(C)C)=O)[CH:23]([CH2:25][CH:26]=[CH2:27])[CH3:24]>>[CH3:21][NH:22][CH:23]([CH2:25]/[CH:26]=[CH:27]/[C:2]1[N:7]=[C:6]2[O:8][CH:9]=[N:10][C:5]2=[CH:4][CH:3]=1)[CH3:24]참가 물질
4
실험 절차
5-Bromooxazolo[5,4-b]pyridine, isomeric by orientation of ring fusion to the previously described 6-bromooxazolo[4,5-b]pyridine, can also be used in the Heck coupling with N-methyl-N-(tert-butoxycarbonyl)4-penten-2-amine. Subsequent removal of the tert-butoxycarbonyl protecting group provides (4E)-N-methyl-5-(5-oxazolo[5,4-b]pyridinyl)-4-penten-2-amine. The required 5-bromooxazolo[5,4-b]pyridine is synthesized from 3-amino-5-bromo-2-pyridinol (3-amino-5-bromo-2-pyridone) by the condensation with formic acid (or a derivative thereof) as described above. 3-Amino-5-bromo-2-pyridinol can be made by bromination (using techniques described by T. Batkowski, Rocz. Chem. 41: 729-741 (1967)) and subsequent tin(II) chloride reduction (according to the method described by S. X. Cai et al., J. Med. Chem. 40(22): 3679-3686 (1997)) of commercially available 3-nitro-2-pyridinol (Aldrich Chemical Company).