3-Isopropoxy-4-(tri-n-butylstannyl)-3-cyclobutene-1,2-dione → HCID 86749353, compound

HRID 1440808Notes

Reaction equation

HRID 1440808 reaction equation
[CH3:1][C:2]1([CH3:24])[C@@H:7]([OH:8])[C@H:6]([N:9]2[CH2:17][C:16]3[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=3)[C:10]2=[O:18])[C:5]2[CH:19]=[C:20](I)[CH:21]=[CH:22][C:4]=2[O:3]1.[CH3:25][CH:26]([O:28][C:29]1[C:30](=[O:47])[C:31](=[O:46])[C:32]=1[Sn](CCCC)(CCCC)CCCC)[CH3:27]>CN(C=O)C.CC#N.[Cu]Cl>[OH:8][C@H:7]1[C@H:6]([N:9]2[CH2:17][C:16]3[C:11](=[CH:12][CH:13]=[CH:14][CH:15]=3)[C:10]2=[O:18])[C:5]2[C:4](=[CH:22][CH:21]=[C:20]([C:32]3[C:31](=[O:46])[C:30](=[O:47])[C:29]=3[O:28][CH:26]([CH3:27])[CH3:25])[CH:19]=2)[O:3][C:2]1([CH3:1])[CH3:24]

Participants

6

Reactant 2

HCID 27366833-Isopropoxy-4-(tri-n-butylstannyl)-3-cyclobutene-1,2-dioneHCID 67733921HCID 67733921, compound

Product 1

HCID 86749353HCID 86749353, compoundYield 16.1%

Reagents, catalysts & solvents 3

HCID 62652Cuprous chlorideCatalystHCID 6228DimethylformamideSolventHCID 6342AcetonitrileSolvent

Procedure

To a solution of 217 mg (0.50 retool) of trans-2-[2,3-dihydro-2,2-dimethyl-3-hydroxy-6-iodo-4H-1-benzopyran-4-yl]-2,3-dihydro-1H-isoindol-1-one, prepared in Example 2, and 235 mg (0.55 mmol) of 3-(1-methylethoxy)-4-(tri-n-butylstannyl)-3-cyclobutene-1,2-dione, as prepared by Liebeskind et. al. (J. Org. Chem. 55, 5359 (1990)), in DMF (620 μL) was added 23 mg (0.03 mmol) of trans-benzyl(chloro)bis(trisphenyl-phosphine) palladium (II) and 8.5 mg (0.04 mmol) of copper (I) chloride. After stirring at ambient temperature for 1.5 h, the reaction mixture was dissolved in hot CH3CN (200 mL) and was washed with hexane. The acetonitrile phase was dried over MgSO4 and was concentrated to a solid, which was then dissolved in hot THF/CH2Cl2 and absorbed onto silica gel. Purification by flash chromatography (65% EtOAc/35% hexane) gave 36 mg (16% yield) of the title compound. Additional compound was prepared in a repeat reaction in 52% yield by purifying with a short flash chromatography column using (CH3CN elution). Repeated crystallizations from CH3CN/Et2O/hexane provided an analytically pure sample, mp>250° C.: 1H-NMR (DMSO-d6 ; 400 MHz) δ7.83 (d, 1 H), 7.78 (dd, 1 H), 7.54-7.66 (m , 3 H), 7.38 (s, 1 H), 7.05 (d, 1 H), 5.86 (d, 1 It), 5.32 (br d, 1 H), 5.24 (septet, 1 H), 4.47-4.48 (br d, 1 H), 3.9-4.1 (br, 2 H), 1.51 (s, 3 H), 1.29 (s, 3 H), 1.25 (d, 3 H), and 1.02 ppm (d, 3 H); mass spectrum (DEI) m/e 447,429, 414. Anal. Calcd. for C26H25NO6. 0.5 H2O: C, 68.41; H, 5.74; N, 3.07 Found: C, 68.31; H, 5.56; N, 3.08.

Workup

  1. washwas washed with hexane
  2. dry with materialThe acetonitrile phase was dried over MgSO4
  3. concentrationwas concentrated to a solid, which
  4. dissolutionwas then dissolved in hot THF/CH2Cl2
  5. customabsorbed onto silica gel
  6. customPurification by flash chromatography (65% EtOAc/35% hexane)

Sources & evidence

ORD record
ord-46af0ee2e4ec4b49b0ee166040dd2865
Source dataset
uspto-grants-1996_03
Patent number
US05500442

Reaction notes

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