Dimethyl oxalate → HCID 386818, compound

HRID 1588001Notes

Reaction equation

HRID 1588001 reaction equation
[C:1]1([S:7]([N:10]2[C:18]3[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=3)[CH:12]=[CH:11]2)(=[O:9])=[O:8])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.C([Li])(C)(C)C.[CH3:24][O:25][C:26](=[O:31])[C:27](OC)=[O:28]>C1COCC1>[C:1]1([S:7]([N:10]2[C:18]3[C:13](=[CH:14][CH:15]=[CH:16][CH:17]=3)[CH:12]=[C:11]2[C:27]([C:26]([O:25][CH3:24])=[O:31])=[O:28])(=[O:9])=[O:8])[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

5

Reactant 3

HCID 11120Dimethyl oxalateHCID 3150171-(Phenylsulfonyl)-1H-indoleHCID 178418306HCID 178418306, compound

Product 1

HCID 386818HCID 386818, compoundYield 34%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

To a solution of N-phenylsulfonyl indole (5.14 g, 20 mmol) in dry THF (100 ml) under argon, and cooled to -65° C., was added t-butyl lithium (13 ml, 22 mmol, 1.7 M in pentane). The solution was allowed to warm to 0° C. and stirred for 1 hr. The above solution was added via canula to a stirred solution of dimethyloxalate (9.5 g, 80 mmol) in THF (250 ml) at 0° C. After 4 hrs at 0° C. the mixture was quenched with saturated aqueous NH4CI and extracted with ethyl acetate (3×100 ml). The dried (MgSO4) extract was evaporated in vacuo, and the residue purified by chromatography over silica gel eluting with hexane/ethyl acetate (b 10:1) to give the α-keto ester 12 (2.3 g, 34%). M.p. 111-112° C. (from ethyl acetate). IR (CHCl3) 3680, 3619, 3415, 3019, 1743, 1692, 1600, 1537 and 1372 cm-1. λmax (ε) (MeOH) 208 (23930), 265 (4460), 275 (4170), 312 (10040) nm. 1H NMR (CDCl3) δ8.06 (1H, d, J=8.5 Hz), 7.78 (2H, d, J=7.5 Hz), 7.58 (1H,d, J=8 Hz), 7.51-7.37 (5H, m), 7.29 (1H, t, J=7.6 Hz), 3.99 (3H, s). 13C NMR (CDCl3) δ177.2, 161.3, 138.5, 136.7, 135.8, 134.1, 129.0, 128.7, 128.5, 127.0, 124.8, 123.4, 122.2, 115.3, 53.3. Anal. calcd for C17H13NO5S C, 59.47; H, 3.82; N, 4.08. Found C, 59.42; H3.84; N, 3.99%.

Workup

  1. customAfter 4 hrs at 0° C. the mixture was quenched with saturated aqueous NH4CI
  2. extractionextracted with ethyl acetate (3×100 ml)
  3. dry with materialThe dried (MgSO4)
  4. extractionextract
  5. customwas evaporated in vacuo
  6. customthe residue purified by chromatography over silica gel eluting with hexane/ethyl acetate (b 10:1)

Sources & evidence

ORD record
ord-a727dd1ba8a74759a81cefea53623aeb
Source dataset
uspto-grants-1993_06
Patent number
US05220016

Reaction notes

Loading…