[6-(5-Bromo-[1,3,4]thiadiazol-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester → [1-Hydroxy-4-methyl-6-([1,3,4]thiadiazol-2-yloxy)-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester

HRID 1798290Notes

Reaction equation

HRID 1798290 reaction equation
[CH2:1]([O:3][C:4](=[O:24])[CH2:5][CH:6]1[O:10][B:9]([OH:11])[C:8]2[CH:12]=[C:13]([O:17][C:18]3[S:19][C:20](Br)=[N:21][N:22]=3)[CH:14]=[C:15]([CH3:16])[C:7]1=2)[CH3:2]>CCO.[Pd]>[CH2:1]([O:3][C:4](=[O:24])[CH2:5][CH:6]1[O:10][B:9]([OH:11])[C:8]2[CH:12]=[C:13]([O:17][C:18]3[S:19][CH:20]=[N:21][N:22]=3)[CH:14]=[C:15]([CH3:16])[C:7]1=2)[CH3:2]

Participants

4

Reactant 1

HCID 58292659[6-(5-Bromo-[1,3,4]thiadiazol-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester

Product 1

HCID 58292715[1-Hydroxy-4-methyl-6-([1,3,4]thiadiazol-2-yloxy)-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl esterYield 70.1%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 702EthanolSolvent

Procedure

A mixture of [6-(5-bromo-[1,3,4]thiadiazol-2-yloxy)-1-hydroxy-4-methyl-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester (0.53 g, 1.28 mmol) and Pd/C (0.5 g) in EtOH (15 mL) was hydrogenated at 45 psi for 1 hour. The mixture was filtered through a pad of celite and concentrated in vacuo. The residue was purified by silica gel flash column chromatography (DCM:MeOH 95:5) to give [1-hydroxy-4-methyl-6-([1,3,4]thiadiazol-2-yloxy)-1,3-dihydro-benzo[c][1,2]oxaborol-3-yl]-acetic acid ethyl ester (0.3 g, 70%). 1H NMR (400 MHz, DMSO): δ 9.15 (s, 1H), 7.40 (s, 1H), 7.28 (s, 1H), 5.52 (d, J=8.8 Hz, 1H), 4.00 (q, J=7.2 Hz, 2H), 3.10 (dd, J=4.0, 15.6 Hz, 1H), 2.52-2.45 (m, 1H), 2.30 (s, 3H), 1.10 (t, J=6.8 Hz, 3H). MS (ESI) m/z=335 [M+H]+.

Workup

  1. filtrationThe mixture was filtered through a pad of celite
  2. concentrationconcentrated in vacuo
  3. customThe residue was purified by silica gel flash column chromatography (DCM:MeOH 95:5)

Sources & evidence

ORD record
ord-2c175237aa85434a93f5c8ba158b1f3c
Source dataset
uspto-grants-2013_01
Patent number
US08343944B2

Reaction notes

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