Acetaldehyde → 2H-1,3-oxazine, tetrahydro-2,4,4,6-tetramethyl-

HRID 848400Notes

Reaction equation

HRID 848400 reaction equation
[CH3:1][C:2]([NH2:8])([CH2:4][CH:5]([OH:7])[CH3:6])[CH3:3].[CH:9](=O)[CH3:10].C1(C)C=CC=CC=1>O>[CH3:9][CH:10]1[NH:8][C:2]([CH3:3])([CH3:1])[CH2:4][CH:5]([CH3:6])[O:7]1

Participants

5

Reactant 3

HCID 177AcetaldehydeHCID 1140TolueneHCID 954054-Amino-4-methyl-2-pentanol

Product 1

HCID 118048782H-1,3-oxazine, tetrahydro-2,4,4,6-tetramethyl-Yield 94%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
20 °C

Procedure

1,170 parts by weight of 2-methyl-2-aminopentan-4-ol is placed in a stirred flask. With external cooling, 440 parts by weight of acetaldehyde is run in over a period of about 40 minutes at 15°-20° C. The reaction mixture is stirred for a further 15 minutes at 20° C. After the addition of 600 parts by volume of toluene, 182 parts by weight of water is separated off over a period of 2 hours by azeotropic distillation. The reaction product is subjected to fractional distillation. After removal of the solvent there is obtained 1,372 parts by weight of 2,4,4,6-tetramethyltetrahydro-1,3-oxazine with a purity (according to gas chromatography) of 98%, equivalent to a yield of 94% of theory, based on 2-methyl-2-aminopentan-4-ol.

Workup

  1. customis run in over a period of about 40 minutes at 15°-20° C
  2. customis separated off over a period of 2 hours by azeotropic distillation
  3. distillationThe reaction product is subjected to fractional distillation
  4. customAfter removal of the solvent there

Sources & evidence

ORD record
ord-10ae905908454cffa09763f229166ec0
Source dataset
uspto-grants-1981_10
Patent number
US04295875

Reaction notes

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