tert-Butanol → tert-Butyl thiophen-3-ylcarbamate

HRID 641618Notes

Reaction equation

HRID 641618 reaction equation
[S:1]1[CH:5]=[CH:4][C:3](C(O)=O)=[CH:2]1.C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=[O:16])C=CC=CC=1.C([N:28]([CH2:31]C)CC)C.[C:33]([OH:37])([CH3:36])([CH3:35])[CH3:34]>>[S:1]1[CH:5]=[CH:4][C:3]([NH:28][C:31](=[O:16])[O:37][C:33]([CH3:36])([CH3:35])[CH3:34])=[CH:2]1

Participants

5

Reactant 4

HCID 6386tert-ButanolHCID 6918Thiophene-3-carboxylic acidHCID 8471TriethylamineHCID 199401P,P-Diphenylphosphinic azide

Product 1

HCID 736476tert-Butyl thiophen-3-ylcarbamateYield 69%

Procedure

3-Thiophenecarboxylic acid (31 g, 0.24 mol), Diphenylphosphoryl azide (57 mL, 0.26 mol) and triethylamine (36 mL, 0.26 mol) were combined in dry tert-butanol (450 mL) and the resulting solution was heated to reflux. After 22 h the cooled solution was concentrated in vacuo to remove solvent. The residue was taken up in diethyl ether (1.5 L) and washed with 5% aqueous citric acid, water and brine (1.5 L each), dried (Na2SO4), and concentrated in vacuo to give the crude product as a tacky tan solid (51 g). Recrystallization from hot ethyl acetate-hexane gave the title compound (33 g, 69%, m.p. 139-41° C.) as shiny off-white needles.

Workup

  1. temperaturethe resulting solution was heated to reflux
  2. concentrationAfter 22 h the cooled solution was concentrated in vacuo
  3. customto remove solvent
  4. washwashed with 5% aqueous citric acid, water and brine (1.5 L each)
  5. dry with materialdried (Na2SO4)
  6. concentrationconcentrated in vacuo
  7. customto give the crude product as a tacky tan solid (51 g)
  8. customRecrystallization from hot ethyl acetate-hexane

Sources & evidence

ORD record
ord-46c35c4a51004ddab05b2d36a38ca455
Source dataset
uspto-grants-2010_04
Patent number
US07696221B2

Reaction notes

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