1-Propylboronic acid catechol ester → Benzyl 6-[(tert-butoxycarbonyl)amino]-2-methyl-3-propylbenzoate

HRID 1725916Notes

Reaction equation

Br[C:2]1[C:3]([CH3:26])=[C:4]([C:15]([NH:18][C:19]([O:21][C:22]([CH3:25])([CH3:24])[CH3:23])=[O:20])=[CH:16][CH:17]=1)[C:5]([O:7][CH2:8][C:9]1[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=1)=[O:6].[CH2:27](B1OC2C=CC=CC=2O1)[CH2:28][CH3:29]>C1COCC1.[Cl-].[Na+].O.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.C1C=CC(P(C2C=CC=CC=2)[C-]2C=CC=C2)=CC=1.Cl[Pd]Cl.[Fe+2]>[C:22]([O:21][C:19]([NH:18][C:15]1[C:4]([C:5]([O:7][CH2:8][C:9]2[CH:14]=[CH:13][CH:12]=[CH:11][CH:10]=2)=[O:6])=[C:3]([CH3:26])[C:2]([CH2:27][CH2:28][CH3:29])=[CH:17][CH:16]=1)=[O:20])([CH3:25])([CH3:24])[CH3:23]

Participants

Conditions

Temperature: 90 °C

Procedure

A mixture of Example 126A (0.52 g, 1.25 mmol), 2-propyl-1,3,2-benzodioxaborole (0.50 g, 3.0 mmol), Pd(dppf)Cl2 (24 mg, 0.03 mmol) and Tl2CO3 (0.75 g, 1.6 mmol) in THF (15 mL) in a scintillation vial was purged with argon, sealed, and shaken at 90° C. for 72 hours. The mixture was treated with brine (25 mL) and extracted with ethyl acetate. The extract was dried (Mg2SO4), filtered, and concentrated. The residue was purified by flash column chromatography on silica gel eluting with 5% ethyl acetate/hexanes to provide the desired product (0.38 g, 80.0%). 1H NMR (CDCl3) δ 0.94 (t, 3H), 1.48 (s, 9H), 1.55 (m, 2H), 2.24 (s, 3H), 2.54 (t, 2H), 5.38 (s, 2H), 7.15 (d, 1H), 7.36-7.46 (m, 5H), 7.77 (d, 1H).

Workup

customsealed
extractionextracted with ethyl acetate
dry with materialThe extract was dried (Mg2SO4)
filtrationfiltered
concentrationconcentrated
customThe residue was purified by flash column chromatography on silica gel eluting with 5% ethyl acetate/hexanes

Sources & evidence

ORD record: ord-64afd9afb5b94a1da8b708ea65e26cd3
Source dataset: uspto-grants-2009_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07491718B2

Reaction notes

Loading…