Ninhydrin → (R)-tert-butyl 1-bromopropan-2-ylcarbamate

HRID 1425532Notizen

Reaktionsgleichung

Reaktionsgleichung von HRID 1425532
O[CH2:2][C@H:3]([NH:5][C:6](=[O:12])[O:7][C:8]([CH3:11])([CH3:10])[CH3:9])[CH3:4].C(Br)(Br)(Br)[Br:14].C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.C1C=C2C(C(O)(O)C(=O)C2=CC=1)=O>>[Br:14][CH2:2][C@H:3]([NH:5][C:6](=[O:12])[O:7][C:8]([CH3:11])([CH3:10])[CH3:9])[CH3:4]

Komponenten

5

Edukt 4

HCID 10236NinhydrinHCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 13200309tert-butyl N-((2R)-1-hydroxypropan-2-yl)carbamate

Produkt 1

HCID 57081792(R)-tert-butyl 1-bromopropan-2-ylcarbamateAusbeute 49,3 %

Versuchsvorschrift

A solution of (R)-tert-butyl 1-hydroxypropan-2-ylcarbamate (100 mg, 571 μmol) and carbon tetrabromide (303 mg, 913 μmol) was cooled on an ice bath. Triphenylphosphine (299 mg, 1141 μmol) was added and the reaction was stirred for 10 min. The reaction was then allowed to warm to r.t. and stirred for 18 hours. After this time, a TLC suggested that the reaction was complete (silica, 50% EtOAc/Hexanes, Ninhydrin stain). The solvent was removed and the product purified by column chromatography (0,5,10,15,20% EtOAc/Hexanes) to yield (R)-tert-butyl 1-bromopropan-2-ylcarbamate (67.1 mg, 0.28 mmol, 49.3%) as a colorless oil that turned solid upon standing. LCMS 238.1 (M+H); 1H NMR (400 MHz, MeOH-d4) δ ppm 1.23 (d, J=6.57 Hz, 3 H), 1.46 (s, 9 H), 3.44 (dd, J=5.56, 1.77 Hz, 2 H), 3.71-3.92 (m, 1 H).

Aufarbeitung

  1. stirringstirred for 18 hours
  2. customThe solvent was removed
  3. customthe product purified by column chromatography (0,5,10,15,20% EtOAc/Hexanes)

Quellen und Nachweise

ORD-Eintrag
ord-667fbf4778c949cfad356013c335ebb3
Quelldatensatz
uspto-grants-2015_01
Patentnummer
USRE045336E1

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