Sodium Hydroxide → Tert-butyl 7-hydroxy-1,3a,4,9b-tetrahydrochromeno[3,4-b]pyrrole-3(2H)-carboxylate

HRID 518137Notes

Reaction equation

B(Br)(Br)Br.C[O:6][C:7]1[CH:8]=[CH:9][C:10]2[CH:19]3[CH:15]([N:16]([C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])[CH2:17][CH2:18]3)[CH2:14][O:13][C:11]=2[CH:12]=1.[OH-].[Na+].C(OC(OC(C)(C)C)=O)(OC(C)(C)C)=O>C(Cl)Cl.O>[OH:6][C:7]1[CH:8]=[CH:9][C:10]2[CH:19]3[CH:15]([N:16]([C:20]([O:22][C:23]([CH3:26])([CH3:25])[CH3:24])=[O:21])[CH2:17][CH2:18]3)[CH2:14][O:13][C:11]=2[CH:12]=1

Participants

Conditions

Temperature: 0 °C

Procedure

A solution of boron tribromide (88 mL, 1 M, 88 mmol) in DCM was added to a solution of tert-butyl 7-methoxy-1,3a,4,9b-tetrahydrochromeno[3,4-b]pyrrole-3(2H)-carboxylate (8.6 g, 29 mmol) in DCM (204 mL) over 30 min at −78° C. The reaction mixture was kept at −78° C. for 30 min and then stirred at 0° C. for 30 min. Water (29 mL) and an aqueous solution of NaOH (95 mL, 3 M) were then added, followed by di-tert-butyl dicarbonate (11.4 g, 52.3 mmol). After stirring for 3 h, the layers were separated. The organic layer was washed with 0.1 N HCl, H2O, and the solvent was removed. The resulting residue was triturated using heptane. The crude product was recovered via filtration and was used in the next reaction step without further purification. MS m/z 235 [M−tBu+H]+

Workup

stirringAfter stirring for 3 h
customthe layers were separated
washThe organic layer was washed with 0.1 N HCl, H2O
customthe solvent was removed
customThe resulting residue was triturated
filtrationThe crude product was recovered via filtration
customwas used in the next reaction step without further purification

Sources & evidence

ORD record: ord-b5c49788735f4c54936004a6d24b4e2e
Source dataset: uspto-grants-2015_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09115147B2

Reaction notes

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