Synthesis of (±)-Isoautumnaline and (±)-Dysoxyline

Abstract

The structures previously assigned to the phenethylisoquinoline alkaloids (-)-isoautumnaline and (+)-dysoxyline have been confirmed by total syntheses of the corresponding racemic substances.

Synthesis and biological activity of substituted 2,4-diaminopyrimidines that inhibit Bacillus anthracis

“…This compound was prepared on a 0.27-mol scale using the method of Nimgirawath [28]. The crude product was recrystallized (4:1 ethanol:water) to give 25.2 g (96%) of 11 as a white solid, mp 71–72 °C (lit [28] mp 71–72 °C).…”

“…The crude product was recrystallized (4:1 ethanol:water) to give 25.2 g (96%) of 11 as a white solid, mp 71–72 °C (lit [28] mp 71–72 °C). IR: 2832, 2730, 2693 cm −1 ; 1 H-NMR (300 MHz): δ 9.83 (s, 1H), 7.85 (d, 1H, J = 1.7 Hz), 7.41 (d, 1H, J = 1.7 Hz), 3.93 (s, 3H), 3.92 (s,3 H); 13 C-NMR (75 MHz): δ 189.7, 154.2, 153.0, 134.7, 133.9, 111.0, 92.1, 60.7, 56.1.…”

“…Conjugate addition of morpholine ( 7 ) to acrylonitrile ( 8 ) [26] generated 3-morpholinopropionitrile ( 9 ) [27] in 95% yield. O -Methylation of 5-iodovanillin ( 10 ) using potassium carbonate and dimethyl sulfate in DMF [28] furnished dimethoxyaldehyde 11 (96%). Conversion of 9 and 11 to 13 was then carried out using a procedure improved from the original synthetic approach [29] (Scheme 3).…”

Approaches to Iodinated Derivatives of Vanillin and Isovanillin

“…Compound 6a has been previously prepared twice. One article 16 gave an analysis for iodine but no experimental data, and the other 5 reported a correct melting point and 1 H-NMR spectrum, but no elemental analysis.…”

“…1–3 A current project in our laboratory required the conversion of 5-iodoisovanillin ethers 6a–d to substituted 2,4-diaminopyrimidines followed by Heck coupling with an unsaturated ketone to generate agents displaying inhibitory activity against Bacillus anthracis , a potential bioterror threat. 4 The chemistry to prepare 5-iodovanillin ethers 6a–d with variation at C-4 is straightforward 5,6 starting from commercial 5-iodovanillin ( 3 ). 7,8 …”