1-Bromopropane → HCID 10375365, compound

Participants

Reaction Steps

The title compound was prepared from 3,4-methylenedioxybenzaldehyde of formula 2 (7.5 g, 50 mmol) by subjecting it to Grignard's reaction with 1-bromopropane by the method described in example 1(i) to give 1-(3,4-methylenedioxyphenyl)-n-butanol of formula 3 (9.4 g, 97%). The secondary alcohol (7.8 g, 40 mmol) was subjected to Vilsmeier reaction with dimethyl formamide-phosphorous oxychloride as described in example 1 (ii) to furnish 2-formyl-1-(3,4-methylenedioxyphenyl)-1-butene (5.0 g, 67%). The resulting aldehyde (2.0 g, 10 mmol) was hydrogenated in presence of Pd/C in methanol to furnish after purification corresponding dihydro derivative (1.0 g, 50%) of formula 5. The dihydro derivative of formula 5 was subjected to Wittig reaction as described in example 1 (iii) followed by saponification to produce 5-(3,4-methylenedioxyphenyl)-4-ethyl-4E-pentenoic acid (0.8 g, 86%) of formula 7. The pentenoic acid (0.75 g, 3.0 mmol) of formula 9 after acid chloride formation with thionyl chloride, and reaction with piperidine was purified by column chromatography on silica gel to give 5-(3,4-methylenedioxyphenyl)-4-ethyl-2E-pentenoic acid piperidine amide of formula 1b (0.8 g, 86%).

Provenance & Evidence