Potassium Bicarbonate → 3-Methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-(trimethylsilyl)isoxazole

HRID 1504797Notes

Reaction equation

[CH3:1][Si:2]([CH3:15])([CH3:14])[C:3]#[C:4][B:5]1[O:9][C:8]([CH3:11])([CH3:10])[C:7]([CH3:13])([CH3:12])[O:6]1.[OH:16]/[N:17]=[C:18](\Cl)/[CH3:19].C(=O)([O-])O.[K+]>COCCOC>[CH3:19][C:18]1[C:4]([B:5]2[O:9][C:8]([CH3:10])([CH3:11])[C:7]([CH3:13])([CH3:12])[O:6]2)=[C:3]([Si:2]([CH3:14])([CH3:15])[CH3:1])[O:16][N:17]=1

Participants

Conditions

Temperature: 50 °C

Procedure

To a solution of trimethyl[(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)ethynyl]silane (240 g, 1.07 mol) in 1,2-dimethoxyethane (8000 mL) was added (1Z)—N-hydroxyethanimidoyl chloride (120 g, 1.28 mol) and potassium hydrogen carbonate (214.4 g, 2.141 mol). The reaction mixture was heated to 50° C. After 16 hours, the reaction mixture was filtered and concentrated under reduced pressure. The residue was purified via chromatography on silica gel (10% ethyl acetate/hexanes, linear gradient) to afford 3-methyl-4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-5-(trimethylsilyl)isoxazole. MS ESI calc'd. for C13H24BNO3Si [M]+ 281. found 281. 1H NMR (400 MHz, CDCl3) δ 2.39 (s, 3H), 1.31 (s, 12H), 0.37 (s, 9H).

Workup

filtrationthe reaction mixture was filtered
concentrationconcentrated under reduced pressure
customThe residue was purified via chromatography on silica gel (10% ethyl acetate/hexanes, linear gradient)

Sources & evidence

ORD record: ord-ff4977858f6749e88081139e4ba138b7
Source dataset: uspto-grants-2015_12
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09216173B2

Reaction notes

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