Dimethylformamide → Tert-butyl 4-(4-bromothiazol-2-yl)piperazine-1-carboxylate

HRID 1051696Notes

Reaction equation

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

Participants

Conditions

Temperature: 120 °C

Procedure

A 100-mL round-bottom flask was charged with 2,4-dibromothiazole (1.00 g, 4.12 mmol), tert-butyl piperazine-1-carboxylate (0.918 g, 4.93 mmol), triethylamine (1.72 mL, 12.35 mmol) and N,N-dimethylformamide (20 mL). The resulting solution stirred for 18 h at 120° C. The reaction mixture was cooled to room temperature, poured into water (50 mL), and extracted with ethyl acetate (3×20 mL). The combined organic layers were dried over anhydrous sodium sulfate, filtered, and concentrated under vacuum. The residue was purified via column chromatography on silica gel (eluting with 10:1, dichloromethane/methanol) to afford tert-butyl 4-(4-bromothiazol-2-yl)piperazine-1-carboxylate (0.350 g, 23%) as brown oil. MS (ESI, pos. ion) m/z 348, 350 [M+H]+.

Workup

temperatureThe reaction mixture was cooled to room temperature
extractionextracted with ethyl acetate (3×20 mL)
dry with materialThe combined organic layers were dried over anhydrous sodium sulfate
filtrationfiltered
concentrationconcentrated under vacuum
customThe residue was purified via column chromatography on silica gel (eluting with 10:1, dichloromethane/methanol)

Sources & evidence

ORD record: ord-4a9609fe637941da8ccfa6fd039f9672
Source dataset: uspto-grants-2016_07
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US09388161B2

Reaction notes

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