Nitrogen → Methyl 2-(5-bromothiophen-2-yl)acetate

HRID 2075003Notes

Reaction equation

HRID 2075003 reaction equation
N#N.[CH3:3][O:4][C:5](=[O:12])[CH2:6][C:7]1[S:8][CH:9]=[CH:10][CH:11]=1.[Br:13]N1C(=O)CCC1=O>C(Cl)(Cl)Cl.C(O)(=O)C>[CH3:3][O:4][C:5](=[O:12])[CH2:6][C:7]1[S:8][C:9]([Br:13])=[CH:10][CH:11]=1

Participants

6

Reactant 3

HCID 947NitrogenHCID 67184N-bromobutanimideHCID 88055Methyl thiophen-2-acetate

Product 1

HCID 12403315Methyl 2-(5-bromothiophen-2-yl)acetateYield 81.7%

Reagents, catalysts & solvents 2

HCID 176Acetic AcidSolventHCID 6212ChloroformSolvent

Procedure

(The following reaction is carried out in an anhydrous N2 atmosphere.) Dissolve thiophene-2-yl-acetic acid methyl ester (42) (2.0 g, 12.8 mmol) in anhydrous chloroform (9.0 mL) and glacial acetic acid (9.0 mL), add N-bromosuccinimide (2.3 g, 13.0 mmol) in portions and stir the mixture for 3 d at rt. Add water to the reaction mixture, separate layers and extract the aqu. layer with dichloromethane. Wash combined organic layer several times with a 1 M aqu. NaOH and water and once with brine and dry it with Na2SO4. Purify the crude product by preparative radial chromatography (CyH/EtOAc 5+1] to obtain (5-bromo-thiophen-2-yl)-acetic acid methyl ester (43) as a yellow oil (2.46 g, 81%) which is used without any further purification. 1H NMR (400 MHz, CDCl3): 3.71 (s, 3 H); 3.75 (s, 2 H); 6.67 (d, 1 H, J=3.8 Hz); 6.88 (d, 1 H, J=3.8 Hz).

Workup

  1. custom(The following reaction
  2. customAdd water to the reaction mixture, separate layers
  3. extractionextract the aqu
  4. washWash
  5. dry with materialNaOH and water and once with brine and dry it with Na2SO4
  6. customPurify the crude product by preparative radial chromatography (CyH/EtOAc 5+1]

Sources & evidence

ORD record
ord-2fa52f5c9f954ecb82bdc82c43368b65
Source dataset
uspto-grants-2011_04
Patent number
US07919532B2

Reaction notes

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