Diethyl Ether → Dimethyl 4-aminothiophene-2,3-dicarboxylate Hydrochloride

HRID 231642Notes

Reaction equation

HRID 231642 reaction equation
O=[C:2]1[CH:6]([C:7]([O:9][CH3:10])=[O:8])[CH:5]([C:11]([O:13][CH3:14])=[O:12])[S:4][CH2:3]1.[ClH:15].[NH2:16]O.CCOCC>C(#N)CC>[ClH:15].[NH2:16][C:2]1[C:6]([C:7]([O:9][CH3:10])=[O:8])=[C:5]([C:11]([O:13][CH3:14])=[O:12])[S:4][CH:3]=1

Participants

5

Reactant 3

HCID 3283Diethyl EtherHCID 443297Hydroxyamine hydrochlorideHCID 2777656Methyl 2,5-anhydro-3-deoxy-3-(methoxycarbonyl)-2-thiopent-4-ulosonate

Product 1

HCID 2808333Dimethyl 4-aminothiophene-2,3-dicarboxylate Hydrochloride

Reagents, catalysts & solvents 1

HCID 7854PropionitrileSolvent

Procedure

3-Oxo-4,5-bismethoxycarbonyltetrahydrothiophene (2.65 g) was dissolved in propionitrile (5 ml) and hydroxylamine hydrochloride (1 g) was added. The mixture was heated under reflux on the steam bath for 11/2 hours by which time it was almost solid. Ether was added to the cooled mixture and the title compound was filtered off. Yield 2.37 g (77.5%) M.P.166°-169° dec. 3-Amino-4,5-bismethoxycarbonylthiophene was liberated from the title compound by treatment with aqueous ammonia followed by bulk distillation (220° C., 0.1 mm Hg) and exhibited 'H n.m.r. δ (CDCl3) 6.40 (1H,s), 4.40 (2H, brs), 3.90, 3.94 (2×3H,s).

Workup

  1. temperatureThe mixture was heated
  2. temperatureunder reflux on the steam bath for 11/2 hours by which time it
  3. filtrationthe title compound was filtered off
  4. distillationfollowed by bulk distillation (220° C., 0.1 mm Hg)

Sources & evidence

ORD record
ord-6b33ab1601fc441f8dc76a3f6c14efe7
Source dataset
uspto-grants-1989_07
Patent number
US04847386

Reaction notes

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