tert-Butanol → 1,1-dimethylethyl N-(3,4-dihydro-7-fluoro-2H-1-benzopyran-8-yl)carbamate

HRID 440686Notes

Reaction equation

HRID 440686 reaction equation
[F:1][C:2]1[CH:11]=[CH:10][C:5]2[CH2:6][CH2:7][CH2:8][O:9][C:4]=2[C:3]=1C(O)=O.C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=[O:22])C=CC=CC=1.C([N:34]([CH2:37]C)CC)C.[C:39]([OH:43])([CH3:42])([CH3:41])[CH3:40]>>[F:1][C:2]1[CH:11]=[CH:10][C:5]2[CH2:6][CH2:7][CH2:8][O:9][C:4]=2[C:3]=1[NH:34][C:37](=[O:22])[O:43][C:39]([CH3:42])([CH3:41])[CH3:40]

Participants

5

Reactant 4

HCID 6386tert-ButanolHCID 8471TriethylamineHCID 199401P,P-Diphenylphosphinic azideHCID 224048173,4-dihydro-7-fluoro-2H-1-benzopyran-8-ylcarboxylic acid

Product 1

HCID 224047711,1-dimethylethyl N-(3,4-dihydro-7-fluoro-2H-1-benzopyran-8-yl)carbamate

Procedure

A stirred solution of 10.2 grams (0.052 mole) of 3,4-dihydro-7-fluoro-2H-1-benzopyran-8-ylcarboxylic acid, 14.3 grams (0.052 mole) of diphenylphosphoryl azide, and 5.3 grams (0.052 mole) of triethylamine in 150 mL of tert.-butanol was heated at reflux for about 18 hours. The reaction mixture was then concentrated under reduced pressure to a residue, which was subjected to column chromatography on silica gel, with 1:4 ethyl acetate:hexane as the eluant. The product-containing fractions were combined and concentrated under reduced pressure, yielding 6.1 grams of 1,1-dimethylethyl N-(3,4-dihydro-7-fluoro-2H-1-benzopyran-8-yl)carbamate. The NMR spectrum was consistent with the proposed structure.

Workup

  1. temperatureat reflux for about 18 hours
  2. concentrationThe reaction mixture was then concentrated under reduced pressure to a residue, which
  3. concentrationconcentrated under reduced pressure

Sources & evidence

ORD record
ord-3350286d675c483b8b81f5d7bd42a9af
Source dataset
uspto-grants-1996_05
Patent number
US05521147

Reaction notes

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