Sulfuric Acid → 2,4,4-trimethyl-5,6-dihydro-1,3(4H)oxazine

HRID 1794610Notes

Reaction equation

HRID 1794610 reaction equation
OS(O)(=O)=O.[CH3:6][C:7](O)([CH3:11])[CH2:8][CH2:9][OH:10].[C:13](#[N:15])[CH3:14]>>[CH3:14][C:13]1[O:10][CH2:9][CH2:8][C:7]([CH3:11])([CH3:6])[N:15]=1

Participants

4

Reactant 3

HCID 1118Sulfuric AcidHCID 6342Acetonitrile2×HCID 247470Isopentyldiol

Product 1

HCID 105346742,4,4-trimethyl-5,6-dihydro-1,3(4H)oxazineYield 50%

Conditions

Temperature
5 °C

Procedure

Acetonitrile(22.6 g, 0.25 mol) was dripped into concentrated H2SO4(150 mL) at 0° C. Upon complete addition of acetonitrile, 3-methyl-butane-1,3-diol(22.6 g, 0.55 mol) was dripped into the reaction vessel over 0.5 h maintaining the reaction temperature at or below 5° C. The resulting mixture was stirred for 1.5 h at 5° C. and then poured onto crushed ice. When the ice melted, the aqueous layer was extracted with ether (2×250 mL). The organic was discarded and the aqueous was treated with 40% NaOH to pH 12. The basic aqueous was extracted with ether. The organic layer was washed with brine and dried (MgSO4). The ether was removed in vacuo at 25° C. affording the desired product as a colorless oil (25.4 g, 50%); 1H NMR (DMSO-d6) δ 4.04 (t, J=6 Hz, 2H), δ 1.72 (s, 3H), δ 1.61 (t, J=6 Hz, 2H), δ 1.07 (s, 6H).

Workup

  1. temperaturemaintaining the reaction temperature at or below 5° C
  2. additionpoured
  3. customonto crushed ice
  4. extractionthe aqueous layer was extracted with ether (2×250 mL)
  5. additionthe aqueous was treated with 40% NaOH to pH 12
  6. extractionThe basic aqueous was extracted with ether
  7. washThe organic layer was washed with brine
  8. dry with materialdried (MgSO4)
  9. customThe ether was removed in vacuo at 25° C.

Sources & evidence

ORD record
ord-cb9498ae4bf048fb953fc2163e626f17
Source dataset
uspto-grants-2006_04
Patent number
US07022850B2

Reaction notes

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