ChemInform Abstract: ASYMMETRIC SYNTHESIS OF (1S)‐(‐)‐TRYPARGINE

Abstract

Aus dem Tryptophanderivat (I) wird auf dem im Formelschema angegebenen Weg das Trypargin (VIII) hergestellt.

Novel synthesis of 3,5-disubstituted pyridines by 1,4-cycloaddition of 1-aza-1,3-butadienes with enamines

“…Conditions: 200 °C for 9 h in PhH solution in a sealed tube. 6 3 mol% was added. cThe yields in parentheses are those obtained without catalyst.…”

“…The IR and NMR spectra of the compound were identical with those of an authentic sample prepared from Ntert-butylamine and -ethylcinnamaldehyde, which was obtained by condensation of benzaldehyde and butyraldehyde. 4i: bp 150 °C (2 mmHg); mp 130 °C (picrate, yellow needles from MeOH); NMR 1.00 (t, 6 H, 2 Me), 2.35 (q, 4 H, 2 CH2), 6.95-7.55 (m, 5 H, Ph), 8.35 General Procedure for the Preparation of Unsymmetrically 3,5-Disubstituted Pyridines 4. An equimolar mixture of the enamine 2 (1.0-100 mmol) and the 1-azabutadiene 3 (1.0-100 mmol) in benzene (2.5-100 mL) was sealed in a stainless steel tube and was heated at 200 °C for 20-24 h unless otherwise noted.…”

“…Found: C, 48.22; , 3.81; N, 15.98. 4k: bp 80 °C (2 mmHg) (a colorless liquid); NMR 1.25 (d, 6 H, 2 Me), 2.26 (s, 3 H, Me), 7.30 (br s, 1 , 4-H), 8.20 (br s, 2 H, 2-H and 6-H); MS, m/e 135 (M+).…”

“…41 was isolated by column chromatography (Si02): mp 121 °C (picrate, yellow needles from MeOH); NMR b 1.22 (t, 3 H, J = 7.5 Hz, Me), 1.25 (d, 6 H, J = 6.8 Hz, 2 Me), 2.63 (q, 2 H, J = 7.5 Hz, CH2), 2.90 (sept, 1 H, J = 6.8 Hz, CH), 7.33 (t, 1H,«7 = 2.0 Hz, 4-H), 8.20 (d, J = 2.0 Hz, 2-H (t, 3 H, Me), 3.00 (q, 2 H, CH2), 7.4-7.7 (m, 6 H, Ph and 4-H), 8.40 (m, 1 , 2-H), 8.67 (m, 1 H, 6-H); MS, m/e 183 (M+).…”

“…Caled for C18H21N507 (picrate): C, 51.55; , 5.05; N, 16.70. Found: C, 51.24; H, 4.97; N, 16.60. 4p was isolated by column chromatography (Si02-CHC13/ benzene) as a colorless liquid: NMR b 1.28 (t, 3 H, Me), 2.70 (q, 2 H, CH2), 6.9-7.5 (m, 6 H, Ph and 4-H), S.2-8.3 (broad, 2 , 2-H and 6-H); MS, m/e 199 (M+).…”