Dimethyl acetylenedicarboxylate → HCID 21923220, compound

HRID 1020898Notes

Reaction equation

HRID 1020898 reaction equation
[C:1]1([C:6]2[N:7]([Si:11]([CH:18]([CH3:20])[CH3:19])([CH:15]([CH3:17])[CH3:16])[CH:12]([CH3:14])[CH3:13])[CH:8]=[CH:9][CH:10]=2)[CH2:5][CH2:4][CH2:3][CH:2]=1.C1(C2C=CN([Si](C(C)C)(C(C)C)C(C)C)C=2)CCCC=1.[C:41]([C:47]([O:49][CH3:50])=[O:48])#[C:42][C:43]([O:45][CH3:46])=[O:44]>CCOCC>[CH:12]([Si:11]([CH:15]([CH3:17])[CH3:16])([CH:18]([CH3:20])[CH3:19])[N:7]1[C:6]2[C:10](=[C:41]([C:47]([O:49][CH3:50])=[O:48])[C:42]([C:43]([O:45][CH3:46])=[O:44])=[C:2]3[CH2:3][CH2:4][CH2:5][C:1]3=2)[CH:9]=[CH:8]1)([CH3:13])[CH3:14]

Participants

5

Reactant 3

HCID 12980Dimethyl acetylenedicarboxylate2×HCID 13291167HCID 13291167, compoundHCID 21923206HCID 21923206, compound

Product 1

HCID 21923220HCID 21923220, compoundYield 5.3%

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent

Conditions

Temperature
110 °C

Procedure

A 2:1 mixture of 2-(cyclopenten-1-yl)-1-(triisopropylsilyl)pyrrole and 3-(cyclopenten-1-yl)-1-(triisopropylsilyl)pyrrole (6.2 g, 21.4 mmol) and dimethyl acetylenedicarboxylate (6.2 g, 43.7 mmol) were heated to 110° C. for 22 h. More dimethyl acetylenedicarboxylate (6.2 g, 43.7 mmol) was added and heating was continued for 6 more h. The resulting orange-brown oil was dissolved in ether (25 mL) then treated with hexanes (50 mL). The same process was repeated 3 more times on the precipitate. The combined ether-hexane soluble fractions were evaporated in vacuo, then heated in vacuo to remove excess dimethyl acetylenedicarboxylate. The residue (3.3 g) was chromatographed (hexanes-ether 75:25) to give 490 mg (5.3% yield) product as a light orange oil. The same product was obtained in 10% yield from pure 2-(cyclopenten-1-yl)-1-(triisopropylsilyl)pyrrole. NMR (CDCl3) δ 7.44 (d, 1H), 7.05 (d, 1H), 3.97 (s, 3H), 3.92 (s, 3H), 3.20 (t, 2H), 3.11 (t, 3H), 2.09 (quintet, 2H), 1.70 (septet, 3H), 1.14 (d, 18H). MS m/e 430 (M+H)+. Anal. Calcd for C24H35NO4Si-0.5H2O: C, 65.71; H, 8.27; N, 3.19. Found: C, 65.51; H, 8.14; N, 2.83.

Workup

  1. temperatureheating
  2. customThe combined ether-hexane soluble fractions were evaporated in vacuo
  3. temperatureheated in vacuo
  4. customto remove excess dimethyl acetylenedicarboxylate
  5. customThe residue (3.3 g) was chromatographed (hexanes-ether 75:25)

Sources & evidence

ORD record
ord-d6cfcad1d4494d999208775b95a1bdb1
Source dataset
uspto-grants-2014_05
Patent number
US08716493B2

Reaction notes

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