Diisopropylethylamine → 4-allyloxy-3,5-dimethyl-benzoic acid N'-(5-isobutyl-thiophene-2-carbonyl)-hydrazide

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Reaction Steps

To a solution of 5-isobutyl-thiophene-2-carboxylic acid (830 mg, 4.51 mmol) and DIPEA (680 mg, 5.27 mmol) in DCM (20 mL) is added TBTU (1.59 g, 4.96 mmol) at rt. The mixture is stirred at rt for 45 min before 4-allyloxy-3,5-dimethyl-benzoic acid hydrazide (993 mg, 4.50 mmol) is added. Stirring is continued for 2 h. The mixture is diluted with ether (200 mL) and washed with 1M aq. HCl (3×50 mL), 1M aq. NaOH (3×50 mL) and brine (50 mL). The org. extract is dried over MgSO4, filtered and evaporated to give the crude 4-allyloxy-3,5-dimethyl-benzoic acid N′-(5-isobutyl-thiophene-2-carbonyl)-hydrazide (1.40 g) as a yellow oil that slowly solidifies; LC-MS: tR=1.02 min, [M+1]+=387.10.

Provenance & Evidence