Triethylamine → Methyl 3-isocyanato-3-methylbutanoate

HRID 1379362

反応式

HRID 1379362 の反応式
C[C:2]([CH3:11])([CH2:6][C:7]([O:9][CH3:10])=[O:8])[C:3](O)=O.C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=[O:19])C=CC=CC=1.C([N:31]([CH2:34]C)CC)C>C1(C)C=CC=CC=1>[N:31]([C:2]([CH3:3])([CH3:11])[CH2:6][C:7]([O:9][CH3:10])=[O:8])=[C:34]=[O:19]

参加物

5

反応物 3

HCID 8471TriethylamineHCID 199401P,P-Diphenylphosphinic azideHCID 126021764-Methoxy-2,2-dimethyl-4-oxobutanoic acid

生成物 1

HCID 15042553Methyl 3-isocyanato-3-methylbutanoate

試薬・触媒・溶媒 1

HCID 1140Toluene溶媒

反応条件

温度
5 °C

実験手順

A solution of 2,2-dimethyl-3-carbomethoxypropionic acid (LeMaul, Bull. Soc. Chim. Fr., 828 (1965), 20 g, 0.125 mol), diphenylphosphorylazide (34.3 g, 0.125 mol) and triethylamine was heated in toluene (150 ml) at 100° C. for 2 h. After cooling to 5° C., the toluene solution was washed successively with 0.5M HCl, aqueous NaHCO3 and brine. Evaporation of the dried solution gave a residue which was chromatographed on silica gel eluting with 60/40 hexane-ether. There was obtained 13 g of methyl 3-isocyanato-3-methylbutanoate as a mobile liquid. A solution of this material in toluene (20 ml) was treated with benzyl alcohol (13 ml) and the resulting mixture heated at reflux for 40 h. Evaporation of the toluene left a residue which was dissolved in methanol (125 ml) and then treated with a solution of NaOH (6.6 g, 0.165 mol) in 22 ml of water. After 5 h, the reaction mixture was partially evaporated, washed with ether and acidified with 6N HCl. Extraction with methylene chloride and evaporation gave 21 g of the desired product. NMR (300 MHz, CDCl3): 1.42 (s,6H), 2.78 (s,2H), 5.08 (s,2H).

後処理

  1. washthe toluene solution was washed successively with 0.5M HCl, aqueous NaHCO3 and brine
  2. customEvaporation of the dried solution
  3. customgave a residue which
  4. customwas chromatographed on silica gel eluting with 60/40 hexane-ether

出典と根拠

ORDレコード
ord-b2a08634846d466e8cf402abee8ceb46
出典データセット
uspto-grants-1997_09
特許番号
US05670675

関連ノート

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