Solketal → Rac-4-(2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-3,5-dimethyl-benzonitrile

HRID 1685712Notes

Reaction equation

HRID 1685712 reaction equation
[CH3:1][C:2]1[CH:3]=[C:4]([CH:7]=[C:8]([CH3:11])[C:9]=1[OH:10])[C:5]#[N:6].[CH3:12][C:13]1([CH3:20])[O:17][CH:16]([CH2:18]O)[CH2:15][O:14]1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.CCOC(/N=N/C(OCC)=O)=O>C1COCC1.C1(C)C=CC=CC=1>[CH3:12][C:13]1([CH3:20])[O:17][CH:16]([CH2:18][O:10][C:9]2[C:8]([CH3:11])=[CH:7][C:4]([C:5]#[N:6])=[CH:3][C:2]=2[CH3:1])[CH2:15][O:14]1

Participants

7

Reactant 4

HCID 7528SolketalHCID 11776TriphenylphosphineHCID 201763,5-Dimethyl-4-hydroxybenzonitrileHCID 5462977Diethyl azodicarboxylate

Product 1

HCID 66692495Rac-4-(2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-3,5-dimethyl-benzonitrileYield 81%

Reagents, catalysts & solvents 2

HCID 1140TolueneSolventHCID 8028TetrahydrofuranSolvent

Procedure

To a solution of 3,5-dimethyl-4-hydroxy-benzonitrile (5.0 g, 34.0 mmol) in THF (40 mL), rac-(2,2-dimethyl-[1,3]dioxolan-4-yl)-methanol (4.49 g, 34.0 mmol) followed by triphenylphosphine (13.4 g, 50.9 mmol) is added. The mixture is cooled with an ice-bath before DEAD (8.87 g, 50.9 mmol, 23.4 mL of a 40% solution in toluene) is added dropwise. The mixture is stirred at rt for 1 h, the solvent is removed in vacuo and the residue is purified by CC on silica gel eluting with heptane:EA 99:1 to 92:8 to give rac-4-(2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-3,5-dimethyl-benzonitrile (7.20 g) as a pale yellow oil; LC-MS: tR=0.99 min, [M+1]+=not detected. b) To a solution of potassium tert.-butylate (6.18 g, 55.1 mmol) in methanol (125 mL), hydroxylamine hydrochloride (5.74 g, 82.7 mmol) is added. To this solution, a solution of rac-4-(2,2-dimethyl-[1,3]dioxolan-4-ylmethoxy)-3,5-dimethyl-benzonitrile (7.20 g, 27.6 mmol) in methanol (40 mL) is added. The mixture is refluxed for 72 h before the solvent is removed in vacuo. The residue is purified by prep. HPLC (XBridge Prep C18, 30×75 mm, 5 μm, 2-95% acetonitrile in water containing 0.5% sat. aq. NH3) to give the title compound (4.85 g) as a pale yellow solid; LC-MS: tR=0.67 min, [M+1]+=295.06; 1H NMR (CDCl3): δ1.43 (s, 3H), 1.48 (s, 3H), 2.29 (s, 6H), 3.76-3.81 (m, 1H), 3.83-3.88 (m, 1H), 3.93-3.99 (m, 1H), 4.17-4.23 (m, 1H), 4.47-4.54 (m, 1H), 5.02 (s br, 1H), 7.28 (s, 2H).

Workup

  1. additionis added
  2. additionis added dropwise
  3. customthe solvent is removed in vacuo
  4. customthe residue is purified by CC on silica gel eluting with heptane:EA 99:1 to 92:8

Sources & evidence

ORD record
ord-770cd16eceff4c158c13697789a4238a
Source dataset
uspto-grants-2012_04
Patent number
US08148410B2

Reaction notes

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