3,5-Diaminobenzoic acid → 6-{4-[(1E)-3-(4-pentyloxyphenoxy)-3-oxoprop-1-enyl]phenoxy}hexyl 3,5 diamino-benzoate

Participants

Reaction Conditions

Reaction Steps

7.50 g (16.85 mmol) 4-pentoxyphenyl (2E)-3-{4-(6-chlorohexyloxy)phenyl}acrylate, 2.82 g (18.54 mmol) 3,5-diaminobenzoic acid and 0.62 g (1.69 mmol) tetrabutylammonium iodide were dissolved in 80 ml dimethylformamide. 3.00 ml (20.22 mmol) 1,8-diazabicyclo[5.4.0]undec-7-ene(1,5-5) (DBU) were added dropwise in the course of 10 minutes. The reaction temperature rose to 30° C. The mixture was then heated at 80° C. for 22 h. The reaction mixture was cooled and then partitioned between ethyl acetate and a saturated sodium bicarbonate solution; the organic phase was washed repeatedly with water, dried over sodium sulphate, filtered and concentrated by rotary evaporation. Chromatography of the residue on 1 kg silica gel using cyclohexane:ethyl acetate 1:1 as eluent yielded 6.6 g of 6-{4-[(1E)-3-(4-pentyloxyphenoxy)-3-oxoprop-1-enyl]phenoxy}hexyl 3,5 diamino-benzoate.

Provenance & Evidence