Hydroxylamine → tert-Butyl (4E)-4-(hydroxyimino)-3,4-dihydro-1'H-spiro[1-benzopyran-2,4'-piperidine]-1'-carboxylate

Participants

Reaction Steps

tert-Butyl 4-oxospiro[chroman-2,4′-piperidine]-1′-carboxylate (450 mg, 1.41 mmol) and hydroxylamine 50 wt % in water (940 μL of 50% w/v, 14 mmol) were combined in methanol (9.0 mL) and heated at reflux. After 24 hours, the reaction mixture was diluted with ethyl acetate and was washed with water. The organics were dried over MgSO4, filtered and evaporated to dryness to yield (E)-tert-butyl 4-(hydroxyimino)spiro[chroman-2,4′-piperidine]-1′-carboxylate (450 mg, 98%). ESI-MS m/z calc. 332.4, found 333.3 (M+1)+; Retention time: 1.68 minutes (3 min run).

Provenance & Evidence