Boron tribromide → HCID 178468704, compound

HRID 396390Notes

Reaction equation

[CH2:1]([O:3][C:4]([C:6]1[NH:7][N:8]=[C:9]([C:11]2[S:15][C:14]([C:16]3[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=3)=[N:13][C:12]=2[CH2:22]OC)[CH:10]=1)=[O:5])[CH3:2].B(Br)(Br)[Br:26]>C(Cl)Cl>[CH2:1]([O:3][C:4]([C:6]1[NH:7][N:8]=[C:9]([C:11]2[S:15][C:14]([C:16]3[CH:21]=[CH:20][CH:19]=[CH:18][CH:17]=3)=[N:13][C:12]=2[CH2:22][Br:26])[CH:10]=1)=[O:5])[CH3:2]

Participants

Conditions

Temperature: -78 °C

Procedure

A −78° C. solution of the above-prepared 5-(4-methoxymethyl-2-phenyl-thiazol-5-yl)-2H-pyrazole-3-carboxylic acid ethyl ester (1.5 g, 4.37 mmole, 1.0 eq) in dry CH2Cl2 (20 ml) was treated with a solution of 1.0M BBr3 in CH2Cl2 (5.24 ml, 5.24 mmole, 1.2 eq) and the mixture stirred at −78° C. for 45 minutes, then allowed to warm to room temperature and stirred for one hour. The reaction mixture was quenched by adding saturated NaHCO3, stirred for 30 minutes then extracted twice with CH2Cl2. The organic phase was washed with brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give a yellow solid. Silica gel chromatography using a gradient elution of (3:2)-(1:1) hexanes-ethyl acetate provided 610 mg (36%) of the title compound as an off white solid. 1H NMR(CDCl3): δ 1.4 (t, 3H), 4.4 (q, 2H), 4.9 (s, 2H), 7.2 (s, 1H), 7.4 (m, 3H), 7.95 (m, 2H), 11.1 (bs, 1H).

Workup

temperatureto warm to room temperature
stirringstirred for one hour
customThe reaction mixture was quenched
additionby adding saturated NaHCO3
stirringstirred for 30 minutes
extractionthen extracted twice with CH2Cl2
washThe organic phase was washed with brine
dry with materialdried over anhydrous sodium sulfate
concentrationconcentrated in vacuo
customto give a yellow solid
washa gradient elution of (3:2)-(1:1) hexanes-ethyl acetate

Sources & evidence

ORD record: ord-66ef4fa370c34b609fbf76cafb2dc665
Source dataset: uspto-grants-2003_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06608087B1

Reaction notes

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