Diisopropylethylamine → 3-(2,4-dimethoxy-phenyl)-5-((1aS,5aR)-1,1,2-trimethyl-1,1a,5,5a-tetrahydro-3-thia-cyclopropa[a]pentalen-4-yl)-[1,2,4]oxadiazole

Participants

Reaction Steps

A mixture of N-hydroxy-2,4-dimethoxy-benzamidine (98 mg, 0.50 mmol), (1aS,5aR)-1,1,2-trimethyl-1,1a,5,5a-tetrahydro-3-thia-cyclopropa[a]pentalene-4-carboxylic acid (111 mg, 0.50 mmol), TBTU (178 mg, 0.55 mmol) and DIPEA (646 mg, 5 mmol) in DMF (4 mL) is stirred at rt for 45 min, then at 110° C. for 1 h. The reaction mixture is directly subjected to prep. HPLC purification (Phenomenex Aqua 75×30 mm, gradient with acetonitrile/water containing 0.5% formic acid) to give 3-(2,4-dimethoxy-phenyl)-5-((1aS,5aR)-1,1,2-trimethyl-1,1a,5,5a-tetrahydro-3-thia-cyclopropa[a]pentalen-4-yl)-[1,2,4]oxadiazole (19 mg) as a colourless lyophilisate; LC-MS: tR=1.17 min, [M+1]+=383.13; 1H NMR (CDCl3): δ 7.89 (d, J=8.8 Hz, 1H), 6.46 (dd, J=2.3, 8.8 Hz, 1H), 6.43 (d, J=2.3 Hz, 1H), 3.83 (s, 3H), 3.74 (s, 3H), 2.96 (dd, J=5.9, 18.8 Hz, 1H), 2.80 (d, J=18.8 Hz, 1H), 2.29 (s, 3H), 1.88-1.78 (m, 2H), 1.02 (s, 3H), 0.63 (s, 3H).

Provenance & Evidence