Chloroacetone → 5-Methyl-3-(2-oxopropyl)-1,3,4-oxadiazol-2(3H)-one

HRID 2381967ノート

反応式

HRID 2381967 の反応式
[CH3:1][C:2]1[O:6][C:5](=[O:7])[NH:4][N:3]=1.C[O-].[Na+].Cl[CH2:12][C:13](=[O:15])[CH3:14]>CO.[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.C(Cl)(Cl)Cl>[CH3:1][C:2]1[O:6][C:5](=[O:7])[N:4]([CH2:12][C:13](=[O:15])[CH3:14])[N:3]=1

参加物

7

反応物 3

HCID 6571ChloroacetoneHCID 53239745-Methyl-2,3-dihydro-1,3,4-oxadiazol-2-oneHCID 10942334Sodium Methoxide

生成物 1

HCID 110409205-Methyl-3-(2-oxopropyl)-1,3,4-oxadiazol-2(3H)-one収率 86%

試薬・触媒・溶媒 3

HCID 74236Tetrabutylammonium Bromide触媒HCID 887Methanol溶媒2 回HCID 6212Chloroform溶媒

実験手順

To a solution of 5-methyl-3H-1,3,4-oxadiazol-2-one (5.509 g, 55.0 mmol) in MeOH (40 mL) is added 25 wt % NaOMe solution in methanol (12.7 mL, 58.8 mmol). The mixture is stirred at rt for 15 min and then concentrated in vacuo. The residue is added to a solution of tetrabutylammonium bromide (0.358 g, 1.08 mmol) and chloro-acetone (4.6 ml, 54.9 mmol) in CHCl3 (33 mL), and the mixture is heated to reflux for 5 h under N2. The mixture is cooled to rt and stirred overnight. The resulting slurry is filtered, and the filtrate is concentrated in vacuo. The residue is purified on a pad of silica gel, eluting with 2:1:1/heptane:EtOAc:DCM to afford 5-methyl-3-(2-oxo-propyl)-3H-1,3,4-oxadiazol-2-one (7.32 g, 86%) as a crystalline solid. MS: 157 (M+H); 1H NMR (300 MHz, CDCl3) δ 4.46 (s, 2H), 2.27 (s, 3H), 2.21 (s, 3H).

後処理

  1. concentrationconcentrated in vacuo
  2. temperaturethe mixture is heated
  3. temperatureto reflux for 5 h under N2
  4. temperatureThe mixture is cooled to rt
  5. stirringstirred overnight
  6. filtrationThe resulting slurry is filtered
  7. concentrationthe filtrate is concentrated in vacuo
  8. customThe residue is purified on a pad of silica gel
  9. washeluting with 2:1:1/heptane

出典と根拠

ORDレコード
ord-22f2223f7287441fbf70f9f9732759b8
出典データセット
uspto-grants-2012_09
特許番号
US08258130B2

反応ノート

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