Carbon tetrabromide → Methyl 4-bromo-2-(tert-butoxycarbonylamino)butanoate

HRID 747890ノート

反応式

HRID 747890 の反応式
C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[CH3:20][O:21][C:22](=[O:35])[C@H:23]([CH2:32][CH2:33]O)[NH:24][C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26].C(Br)(Br)(Br)[Br:37]>C(Cl)Cl>[CH3:20][O:21][C:22](=[O:35])[CH:23]([NH:24][C:25]([O:27][C:28]([CH3:31])([CH3:30])[CH3:29])=[O:26])[CH2:32][CH2:33][Br:37]

参加物

5

反応物 3

HCID 11205Carbon tetrabromideHCID 11776TriphenylphosphineHCID 10561607Methyl N-(tert-butoxycarbonyl)-L-homoserinate

生成物 1

HCID 6857808Methyl 4-bromo-2-(tert-butoxycarbonylamino)butanoate収率 20.2%

試薬・触媒・溶媒 1

HCID 6344Dichloromethane溶媒2 回

実験手順

A solution of triphenylphosphine (2.20 g, 8.39 mmol) in dry CH2Cl2 (20 mL) was added dropwise via syringe to a solution of N-Boc homoserine methyl ester 18 (8.39 mmol) and carbon tetrabromide (4.18 g, 12.60 mmol) in dry CH2Cl2 (20 mL). The resulting dark solution was stirred at room temperature for 16 h. Hexanes was added and precipitates were removed by suction filtration. The filtrate was concentrated under reduced pressure and subject to flash silica gel column chromatography using ethyl acetate/hexanes (1:10, v/v then 1:6, v/v) to give the desired product 19 as a yellow oil (501 mg, 20% overall yield from homoserine). 1H NMR (300 MHz, CDCl3) δ 1.45 (s, 9H), 2.12-2.48 (m, 2H), 3.39-3.47 (m, 2H), 3.78 (s, 3H), 4.33-4.48 (m, 1H), 5.10-5.22 (m, 1H). m/z (ESI) 296 [C10H18BrNO4+H]+.

後処理

  1. customprecipitates
  2. customwere removed by suction filtration
  3. concentrationThe filtrate was concentrated under reduced pressure

出典と根拠

ORDレコード
ord-7c60470d589f413da62386b94e28a030
出典データセット
uspto-grants-2008_07
特許番号
US07399766B2

反応ノート

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