N-bromobutanimide → tert-Butyl (2-bromothiophen-3-yl)carbamate

HRID 1990074Notes

Reaction equation

HRID 1990074 reaction equation
C1C(=O)N([Br:8])C(=O)C1.[C:9]([O:13][C:14](=[O:21])[NH:15][C:16]1[CH:20]=[CH:19][S:18][CH:17]=1)([CH3:12])([CH3:11])[CH3:10]>ClCCl>[C:9]([O:13][C:14](=[O:21])[NH:15][C:16]1[CH:20]=[CH:19][S:18][C:17]=1[Br:8])([CH3:12])([CH3:10])[CH3:11]

Participants

4

Reactant 2

HCID 67184N-bromobutanimideHCID 736476tert-Butyl thiophen-3-ylcarbamate

Product 1

HCID 13164363tert-Butyl (2-bromothiophen-3-yl)carbamate

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Conditions

Temperature
65 °C

Procedure

Add NBS (8.9 g, 0.05 mol) to a boiling solution of 3-thiophenyl-carbamic acid tert-butyl ester (10.0 g, 0.05 mol) in dichloromethane (500 mL) in small portions and stir the mixture at 65° C. for 20 min. Cool down, remove solvent in vacuo and purify the crude material by flash chromatography (silica gel) eluting with hexanes/diethyl ether 19:1 to obtain 11.1 g (80%) as a white solid: 1H NMR (CDCl3) δ: 7.55 (br s, 1H), 7.24 (d, J=4.0 Hz, 1H), 6.56 (br s, 1H), 1.52 (s, 9H).

Workup

  1. temperatureCool down
  2. customremove solvent in vacuo
  3. custompurify the crude material by flash chromatography (silica gel)
  4. washeluting with hexanes/diethyl ether 19:1
  5. customto obtain 11.1 g (80%) as a white solid

Sources & evidence

ORD record
ord-8299d3cf9c394f2e8226ca6558f7a1a1
Source dataset
uspto-grants-2010_01
Patent number
US07642361B2

Reaction notes

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