Triethylamine → Methyl 3-isocyanato-3-methylbutanoate

HRID 1078114

Reaktionsgleichung

Reaktionsgleichung von HRID 1078114
C([O:8][C:9]([NH:11][C:12]([CH3:18])([CH3:17])[CH2:13][C:14]([OH:16])=[O:15])=O)C1C=CC=CC=1.[CH3:19]C(C)(CC(OC)=O)C(O)=O.C1(P(N=[N+]=[N-])(C2C=CC=CC=2)=O)C=CC=CC=1.C(N(CC)CC)C>C1(C)C=CC=CC=1>[N:11]([C:12]([CH3:18])([CH3:17])[CH2:13][C:14]([O:16][CH3:19])=[O:15])=[C:9]=[O:8]

Komponenten

6

Edukt 4

HCID 8471TriethylamineHCID 199401P,P-Diphenylphosphinic azideHCID 126021764-Methoxy-2,2-dimethyl-4-oxobutanoic acidHCID 145510073-(((Benzyloxy)carbonyl)amino)-3-methylbutanoic acid

Produkt 1

HCID 15042553Methyl 3-isocyanato-3-methylbutanoate

Reagenzien, Katalysatoren, Lösungsmittel 1

HCID 1140TolueneLösungsmittel

Reaktionsbedingungen

Temperatur
5 °C

Versuchsvorschrift

3-(Benzyloxycarbonylamino)-3-methylbutanoic Acid. 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).

Aufarbeitung

  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

Quellen und Nachweise

ORD-Eintrag
ord-091d12cdba134398bec44cfc01c1cdbf
Quelldatensatz
uspto-grants-1996_08
Patentnummer
US05545750

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