Hydrochloric Acid → 1-(5-Bromo-7-pyridin-2-yl-benzothiazol-2-yl)-3-ethyl-urea

HRID 1010674Notes

Reaction equation

[Br:1][C:2]1[CH:3]=[C:4](Br)[C:5]2[S:9][C:8]([NH:10][C:11]([NH:13][CH2:14][CH3:15])=[O:12])=[N:7][C:6]=2[CH:16]=1.[Br-].[N:19]1[CH:24]=[CH:23][CH:22]=[CH:21][C:20]=1[Zn+].Cl>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.O>[Br:1][C:2]1[CH:3]=[C:4]([C:20]2[CH:21]=[CH:22][CH:23]=[CH:24][N:19]=2)[C:5]2[S:9][C:8]([NH:10][C:11]([NH:13][CH2:14][CH3:15])=[O:12])=[N:7][C:6]=2[CH:16]=1

Participants

Conditions

Temperature: 55 °C

Procedure

A stirred mixture of the 1-(5,7-dibromo-benzothiazol-2-yl-3-ethyl urea (2.62 g, 0.00687 mol) and Dichlorobis(triphenylphosphine)-palladium (0.48 g 0.000687 mol), under nitrogen, was treated in one portion, via a syringe, with 2-pyridyl zinc bromide solution (0.5M solution in THF, 7.66 g, 0.0344 mol). The reaction mixture was heated, with stirring, at 55° C. for 18 hours, allowed to cool and poured into 500 ml of water containing ˜5 ml of conc hydrochloric acid. The suspension was stirred and the solid filtered off, washed with water, followed by 20 ml of 1:1 DCM/Methanol mixture to give the crude 1-(5-Bromo-7-pyridin-2-yl-benzothiazol-2-yl)-3-ethyl-urea (1.43 g). This was purified by “flash” silica chromatography using 0 to 100% hexane/ethyl acetate followed by 0 to 100% methanol in ethyl acetate to elute the required product as a beige solid (1.1 g).

Workup

temperatureThe reaction mixture was heated
temperatureto cool
stirringThe suspension was stirred
filtrationthe solid filtered off
washwashed with water

Sources & evidence

ORD record: ord-a6ef806caed44a14894e7daf2f38b3b1
Source dataset: uspto-grants-2011_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07977340B2

Reaction notes

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