Diethyl Oxalate → HCID 178470406, compound

HRID 1295067Notes

Reaction equation

HRID 1295067 reaction equation
CC1(C)C2C1CCC2=O.C(OCC)(=O)C(OCC)=O.CC(C)([O-])C.[K+].[CH2:26]([O:28][C:29](=[O:41])[C:30]([CH:32]1[CH2:37][CH:36]2[CH:34]([C:35]2([CH3:39])[CH3:38])[C:33]1=O)=O)[CH3:27].Cl.[NH2:43][NH2:44]>C(O)C.O>[CH2:26]([O:28][C:29]([C:30]1[NH:44][N:43]=[C:33]2[C:32]=1[CH2:37][CH:36]1[C:35]([CH3:39])([CH3:38])[CH:34]12)=[O:41])[CH3:27]

Participants

8

Conditions

Temperature
80 °C

Procedure

(±)-6,6-Dimethyl-bicyclo[3.1.0]hexan-2-one (1.49 g, 12.0 mmol), diethyl oxalate (2.46 g, 16.8 mmol) and potassium t-butoxide (18.0 mL, 1M in THF, 18.0 mmol) were stirred in ethanol (40 mL) at room temperature for 2 hours. The desired (6,6-dimethyl-2-oxo-bicyclo[3.1.0]hex-3-yl)-oxo-acetic acid ethyl ester was observed by LCMS (m/z (ES+): 247 [M+Na]+, 225 [M+H]+) but not isolated. Hydrazine monohydrochloride (0.168 g, 24.4 mmol) in water (2.0 mL) was added and the solution heated to 80° C. for 18 hours. Solvent was removed under reduced pressure and the resulting oil poured into 0.1M aqueous hydrochloric acid (30 mL) and extracted into DCM (200 mL). Solvent was removed under reduced pressure and the residue purified by column chromatography (0–50% EtOAc/n-hexane, silica) to give (±)-1,1-dimethyl-1a,3,5,5a-tetrahydro-1H-2,3-diaza-cyclopropa[a]pentalene-4-carboxylic acid ethyl ester as a pale yellow oil which solidified upon standing. m/z (ES+): 243 [M+Na]+, 221 [M+H]+, 175 [M-OEt]+; 1H NMR (CD3OD): δ 4.4–4.3 (m, 2H, OCH2), 2.90 (dd, 1H, J1=17.5, J2=6.9), 2.65 (d, 1H, J=17.5), 2.1–2.0 (m, 1H), 1.95 (t, 1H, J=12.9), 1.37 (td, J1=7.1, J2=2.0), 1.13 (s, 3H, exo-CH3), 0.74 (d, 3H, J=2.0, endo-CH3).

Workup

  1. customnot isolated
  2. customSolvent was removed under reduced pressure
  3. additionthe resulting oil poured into 0.1M aqueous hydrochloric acid (30 mL)
  4. extractionextracted into DCM (200 mL)
  5. customSolvent was removed under reduced pressure
  6. customthe residue purified by column chromatography (0–50% EtOAc/n-hexane, silica)

Sources & evidence

ORD record
ord-ce69b36ae94d406798964bc289dbb017
Source dataset
uspto-grants-2007_07
Patent number
US07241792B2

Reaction notes

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