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

HRID 1425532ノート

反応式

HRID 1425532 の反応式
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]

参加物

5

反応物 4

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

生成物 1

HCID 57081792(R)-tert-butyl 1-bromopropan-2-ylcarbamate収率 49.3%

実験手順

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).

後処理

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

出典と根拠

ORDレコード
ord-667fbf4778c949cfad356013c335ebb3
出典データセット
uspto-grants-2015_01
特許番号
USRE045336E1

反応ノート

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