反应详情

Treat a solution of 3,3-dimethylcyclobutylcarboxylic acid (0.500 g, 3.90 mmol) and oxalyl chloride (0.512 mL, 5.85 mmol) in DCM (30 mL) with catalytic DMF (1 drop), stir at RT for 4 h, concentrate to dryness, add additional DCM and concentrate to dryness again. Dissolve the residue in THF (10 mL), add drop-wise to a solution of NH4OH (2 mL, 51.4 mmol) in THF (20 mL), and stir at RT overnight. Extract with EtOAc (2×), wash the combined organics with brine, dry over MgSO4 and concentrate to dryness to afford the title compound (440 mg, 89%) as a white solid. 1H NMR (400 MHz, DMSO-d6): δ 7.07 (s, 1H); 6.63 (s, 1H); 2.86 (m, 1H); 1.85 (m, 2H); 1.74 (m, 2H); 1.10 (s, 3H); 1.00 (s, 3H); MS(ESI) m/z: 128.2 (M+H+).

1. concentrationconcentrate to dryness
2. additionadd additional DCM
3. concentrationconcentrate to dryness again
4. dissolutionDissolve the residue in THF (10 mL)
5. additionadd
6. stirringstir at RT overnight
7. extractionExtract with EtOAc (2×)
8. washwash the combined organics with brine
9. dry with materialdry over MgSO4
10. concentrationconcentrate to dryness