Dimethylformamide → 7-{[1-(4-Chlorophenyl)cyclopropyl]carbonyl}-4,4-dimethyl-1-oxa-7-azaspiro[4,4]nonane

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Reaction Steps

A mixture of tert-butyl 2,3,3-trimethyl-1-oxa-6-azaspiro[3.4]octane-6-carboxylate (25.0 mg, 0.0000979 mol) and tert-butyl 4,4-dimethyl-1-oxa-7-azaspiro[4.4]nonane-7-carboxylate (25.0 mg, 0.0000979 mol) was treated with 1 mL of TFA at rt for 30 min. The volatiles were removed in-vacuo and the resultant TFA salt was used directly in next step. To a mixture of the above made TFA salt in N,N-dimethylformamide (0.50 mL, 0.0064 mol) were added 1-(4-chlorophenyl)cyclopropanecarboxylic acid (38.5 mg, 0.000196 mol) and benzotriazol-1-yloxytris(dimethylamino)phosphonium hexafluorophosphate (104 mg, 0.000235 mol), followed by N,N-diisopropylethylamine (0.0853 mL, 0.000490 mol). The mixture was stirred at rt for 2 h and then the product was isolated and purified by RP-HPLC. LCMS (M+H) 334.2.

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