Syntheses of Nitrogen Heterocycles from Pyridines

Ar Cl Me2NH (4 equiv.) EtOH, 50 °C 57% yield, 2 steps then NaOH/H2O n-BuOH, 100 °C CONR2 dihydropyrrole core of porothramycins ...
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Syntheses of Nitrogen Heterocycles from Pyridines Christopher D. Vanderwal, Department of Chemistry, University of California–Irvine substituted indoles with propenal group at C3

Suzuki coupling

R1

R

R1

CHO

BrCN, EtOH/H2O

X

R

63–87% yield NH2

X

N H

N

H2O R1

R = 4-OMe, 5-OMe, 4-CF3, 5-CF3, 4-F, 5-Cl, 6-Br R1 = H, Me X = CH, N

BrCN

R

N R X

N H

R1

R1

CN

R1

X R H2N

N

X Br

N H

CN

R

N

X

CN

N H

N

CN

6π retro electrocyclization, or expulsion of the electron-deficient cyanamide followed by tautomerization R1O

CONR2

H

Cl NO2

NO2

NHBz

N

n-BuOH, 100 °C

HN

NHBz

Me2NH (4 equiv.) EtOH, 50 °C N Ar

Cl

then NaOH/H2O 57% yield, 2 steps

CHO N Bz

dihydropyrrole core of porothramycins

N

X O Y

porothramycin A : R=Me, R1=H, X=OMe, Y=H porothramycin B : R=Me, R1=Me, X=OMe, Y=H anthramycin : R=H, R1=Me, X=OH, Y=Me