Triethylamine → [5-Methoxy-3-methyl-2-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-benzyloxy]-acetic acid tert-butyl ester

HRID 723159Notes

Reaction equation

[C:1]([O:5][C:6](=[O:20])[CH2:7][O:8][CH2:9][C:10]1[CH:15]=[C:14]([O:16][CH3:17])[CH:13]=[C:12]([CH3:18])[C:11]=1Br)([CH3:4])([CH3:3])[CH3:2].C(N(CC)CC)C.[CH3:28][C:29]1([CH3:36])[C:33]([CH3:35])([CH3:34])[O:32][BH:31][O:30]1>O1CCOCC1.CCOC(C)=O.Cl[Pd](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1>[C:1]([O:5][C:6](=[O:20])[CH2:7][O:8][CH2:9][C:10]1[CH:15]=[C:14]([O:16][CH3:17])[CH:13]=[C:12]([CH3:18])[C:11]=1[B:31]1[O:32][C:33]([CH3:35])([CH3:34])[C:29]([CH3:36])([CH3:28])[O:30]1)([CH3:4])([CH3:3])[CH3:2]

Participants

Conditions

Temperature: 80 °C

Procedure

A solution of (2-bromo-5-methoxy-3-methyl-benzyloxy)-acetic acid tert-butyl ester ((Example 192: step d) 1.19 g, 3.45 mmol) in dioxane (10 mL) was treated with PdCl2(PPh3)2 (0.242 g, 0.345 mmol) and triethylamine (2.88 mL, 20.7 mmol). 4,4,5,5-Tetramethyl-1,3,2-dioxaborolane (1.00 mL, 6.89 mmol) was added slowly and the mixture heated to 80° C. 15 h. The reaction was diluted with EtOAc and washed with brine (2×50 mL). The organic layer was dried over MgSO4 and concentrated in vacuo. Silica gel chromatography (25% EtOAc in hexanes) afforded the product [5-methoxy-3-methyl-2-(4,4,5,5-tetramethyl-[1,3,2]dioxaborolan-2-yl)-benzyloxy]-acetic acid tert-butyl ester (0.793 g, 58%) as a brown oil. The crude material was used directly in the next reaction.

Workup

custom15 h
washwashed with brine (2×50 mL)
dry with materialThe organic layer was dried over MgSO4
concentrationconcentrated in vacuo

Sources & evidence

ORD record: ord-6b103f7f3246455da29f3d4501041139
Source dataset: uspto-grants-2006_11
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07138530B2

Reaction notes

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