N-Methylbutylamine → N-methyl-12,13-Bis(4-methoxyphenyl)-11-pentadecenoic amide

Participants

Reaction Steps

To a cooled solution of alcohol 3 (710 mg, 1.56 mmol) in acetone (17 ml) was added Jones' reagent (8N-chromic acid solution, 0.77 ml). After 30 minutes, isopropanol (5 ml) was added and the mixture was poured in water and extracted three times with ethyl acetate. The organic layer was washed twice with brine, dried over magnesium sulfate and evaporated to dryness. The crude 12,13-Bis (4-methoxyphenyl)-11-pantadecenoic acid was used in the next step without purification. To its solution in anhydrous methylene chloride (4 ml) at -10° C. was added, under stirring, triisobutylamine (470 μl, 1.96 mmol) and isobutylchloroformate (280 μl, 2.1 mmol). After 40 minutes, N-methylbutylamine (1.5 ml) was added and the mixture was stirred at room temperature during 1 hour. Methylene chloride (50 ml) was added. The organic solution was washed with 1N HCl, saturated sodium bicarbonate solution and water (3X), dried on magnesium sulfate and evaporated to dryness. The residue was purified by "Flash chromatography" on silica gel (Kieselgel 60, Merck, under 0.063 mm, 50 g). Elution with a mixture of hexane-ethyl acetate (4:1 v/v) gave N-butyl, N-methyl-12,13-Bis (4-methoxyphenyl)-11-pentadecenoic amide (4), (549 mg, 68%) colorless oil; IR νmax (neat), 1640, 1600 cm-1 ; UV γmax (log ε)=230, (4.39) nm; 1H-NMR (δ, CDCl3), 0.85-0.98 (6H, m, 2--CH2CH3), 2.27 (2H, t, J=7.1 Hz, CH2CON), 2.91 and 2.96 (3H, 2s, --NCH3), 3.25-3.36 (3H, m, --NCH2 and CH3CH2CH--), 3.77 and 3.78 (6H, 2s, OCH3), 5.50 (1H, J=7.1 Hz, --C=CH--) and 6.69-7.01 (8H, m, H--Ar) ppm; MS m/e=521 (M+).

Provenance & Evidence