Potassium Hydroxide → Spiro[3,1-benzoxazine-4,1'-cyclobutan]-2(1H)-one

HRID 458554Notes

Reaction equation

HRID 458554 reaction equation
O[C:2]1([C:6]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=2[NH:12][C:13](=[O:19])[O:14]C(C)(C)C)[CH2:5][CH2:4][CH2:3]1.[OH-].[K+]>C(O)C>[C:2]12([C:6]3[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=3[NH:12][C:13](=[O:14])[O:19]1)[CH2:3][CH2:4][CH2:5]2

Participants

4

Reactant 2

HCID 14797Potassium HydroxideHCID 18442665Tert-butyl [2-(1-hydroxycyclobutyl)phenyl]carbamate

Product 1

HCID 18442664Spiro[3,1-benzoxazine-4,1'-cyclobutan]-2(1H)-oneYield 58%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of tert-butyl [2-(1-hydroxycyclobutyl)phenyl]carbamate (0.86 g, 3.3 mmol) in ethanol (30 mL) was stirred with potassium hydroxide (0.39 g, 6.9 mmol) at room temperature for 3 hours. The product was extracted with ethyl acetate (50 mL), dried with sodium sulfate, and concentrated to give spiro[3,1-benzoxazine-4,1′-cyclobutan]-2(1H)-one (0.36 g, 58%) as a white solid. 1H NMR (DMSO-d6): δ 10.21 (s, 1H), 7.47 (dd, 1H, J=7.6, 1.2 Hz), 7.28 (td, 1H, J=7.6, 1.4 Hz), 7.08 (td, 1H, J=7.5, 1.2 Hz), 6.9 (dd, 1H, J=7.9, 0.9 Hz), 2.49–2.41 (m, 2H), 2.06–1.96 (m, 2H), 1.88–1.77 (m, 2H). MS (ESI) m/z 190 ([M+H]+).

Workup

  1. extractionThe product was extracted with ethyl acetate (50 mL)
  2. dry with materialdried with sodium sulfate
  3. concentrationconcentrated

Sources & evidence

ORD record
ord-f3c532d37d78479cb87223e0cf5e6e33
Source dataset
uspto-grants-2007_03
Patent number
US07192956B2

Reaction notes

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