Triphenylphosphine → 6,7-Dihydro-2H-pyrano[2,3-c]pyridazin-3(5H)-one

HRID 2233202Notes

Reaction equation

HRID 2233202 reaction equation
O[CH2:2][CH2:3][CH2:4][C:5]1[C:6](=[O:12])[NH:7][NH:8][C:9](=[O:11])[CH:10]=1.C1(P(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.N(C(OC(C)C)=O)=NC(OC(C)C)=O>C1COCC1>[N:7]1[NH:8][C:9](=[O:11])[CH:10]=[C:5]2[CH2:4][CH2:3][CH2:2][O:12][C:6]=12

Participants

5

Reactant 3

HCID 11776TriphenylphosphineHCID 75555Diisopropyl diazene-1,2-dicarboxylateHCID 675266004-(3-Hydroxypropyl)-1,2-dihydro-3,6-pyridazinedione

Product 1

HCID 675269516,7-Dihydro-2H-pyrano[2,3-c]pyridazin-3(5H)-oneYield 79.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A suspension of 4-(3-hydroxypropyl)-1,2-dihydro-3,6-pyridazinedione (1.48 g, 8.7 mmol) in THF (105 ml) was held in an ultrasound bath for 5 minutes, then cooled under argon in an ice bath. Triphenylphosphine (3.67 g, 14 mmol) was added, followed by diisopropyl azodicarboxylate (2.76 ml, 14 mmol). After 30 minutes the solvent was evaporated and the residue kept under high vacuum overnight. Chromatography, eluting first with 2.5% methanol/dichloromethane until triphenylphosphine oxide was removed and then with 5% methanol/dichloromethane, gave the product as an off-white solid (1.049 g, 79%).

Workup

  1. temperaturecooled under argon in an ice bath
  2. customAfter 30 minutes the solvent was evaporated
  3. customkept under high vacuum overnight
  4. washChromatography, eluting first with 2.5% methanol/dichloromethane until triphenylphosphine oxide
  5. customwas removed

Sources & evidence

ORD record
ord-5be387ec518b4cd3b9190140a1012f83
Source dataset
uspto-grants-2010_05
Patent number
US07709483B2

Reaction notes

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