Cesium carbonate → (S)-1'-bromo-2'-(neopentyloxy)-7'-(pyridin-3-yl)-5H-spiro[oxazole-4,9'-xanthen]-2-amine

HRID 1970373Notes

Reaction equation

[NH2:1][C:2]1[O:3][CH2:4][C@@:5]2([N:27]=1)[C:18]1[C:17]([Br:19])=[C:16]([OH:20])[CH:15]=[CH:14][C:13]=1[O:12][C:11]1[C:6]2=[CH:7][C:8]([C:21]2[CH:22]=[N:23][CH:24]=[CH:25][CH:26]=2)=[CH:9][CH:10]=1.C(=O)([O-])[O-].[Cs+].[Cs+].I[CH2:35][C:36]([CH3:39])([CH3:38])[CH3:37]>CN(C=O)C>[Br:19][C:17]1[C:18]2[C@:5]3([CH2:4][O:3][C:2]([NH2:1])=[N:27]3)[C:6]3[C:11](=[CH:10][CH:9]=[C:8]([C:21]4[CH:22]=[N:23][CH:24]=[CH:25][CH:26]=4)[CH:7]=3)[O:12][C:13]=2[CH:14]=[CH:15][C:16]=1[O:20][CH2:35][C:36]([CH3:39])([CH3:38])[CH3:37]

Participants

Conditions

Temperature: 110 °C

Procedure

A vial was charged with (S)-2-amino-1′-bromo-7′-(pyridin-3-yl)-5H-spiro[oxazole-4,9′-xanthen]-2′-ol (163 mg, 0.384 mmol), cesium carbonate (375 mg, 1.152 mmol), and DMF (2.0 mL). The mixture was stirred for 10 min, then 1-iodo-2,2-dimethylpropane (102 μL, 0.768 mmol) was added. The vial was sealed and heated in a Biotage Initiator microwave reactor for 2 h at 110° C. LCMS at this time shows no starting material and mainly desired product. The mixture was partitioned between water and EtOAc. Brine was added to break up the emulsion that formed and this was partially successful. The aqueous layer was extracted with EtOAc (2×), and the combined organic extracts were dried over sodium sulfate, filtered, and evaporated. The residue was chromatographed on a 50-g SNAP column, eluting with 0-70% of a 90:10:1 mix of DCM/MeOH/NH4OH in DCM to give (S)-1′-bromo-2′-(neopentyloxy)-7′-(pyridin-3-yl)-5H-spiro[oxazole-4,9′-xanthen]-2-amine as an off-white solid after evaporation from DCM/hexane.

Workup

customThe vial was sealed

Sources & evidence

ORD record: ord-daccecac80b7465faba4eb6de7657f49
Source dataset: uspto-grants-2013_04
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08426447B2

Reaction notes

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