Hydrochloric Acid → HCID 57626218, compound

Participants

Reaction Conditions

Reaction Steps

To a magnetically stirred solution of ethyl 1-(n-pentyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxylate (Intermediate (V-1) (11.76 g, 38.74 mmol) in tetrahydrofuran (100 ml) and water (100 ml) was added lithium hydroxide (1.86 g, 77.5 mmol) and the resulting mixture was heated at 70° C. for 1 hour. The reaction mixture was allowed to attain room temperature and diethyl ether (200 ml) and concentrated hydrochloric acid (7 ml) were added. The organic layer was separated, washed three times with water and with brine and subsequently dried over Na2SO4, filtered and concentrated in vacuo to give 1-(n-pentyl)-5-phenyl-4,5-dihydro-(1H)-pyrazole-3-carboxylic acid (Intermediate (VI-1) (7.9 g, 74% yield) as an oil. 1H-NMR (400 MHz, CDCl3) δ 0.84 (t, J=7, 3H), 1.15-1.28 (m, 4H), 1.53-1.65 (m, 2H), 2.92 (dd, J=17 and 13, 1H), 3.02-3.11 (m, 1H), 3.18-3.27 (m, 1H), 3.44 (dd, J=17 and 13, 1H), 4.75 t, J=13, 1H), 7.31-7.41 (m, 5H), 7.42-9.00 (br s, 1H).

Provenance & Evidence