Formaldehyde → Ethyl 3,4,5-trimethyl-1H-pyrrole-2-carboxylate

HRID 1834408Notes

Reaction equation

HRID 1834408 reaction equation
[CH3:1][C:2]1[NH:3][C:4]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[C:5]([CH3:7])[CH:6]=1.I.[CH2:14]=O.[PH2](O)=O.[OH-].[NH4+]>C(O)(=O)C>[CH3:1][C:2]1[NH:3][C:4]([C:8]([O:10][CH2:11][CH3:12])=[O:9])=[C:5]([CH3:7])[C:6]=1[CH3:14]

Participants

7

Reactant 5

HCID 712FormaldehydeHCID 14923Ammonium HydroxideHCID 24841Hydrogen iodideHCID 1374771H-Pyrrole-2-carboxylic acid, 3,5-dimethyl-, ethyl esterHCID 4124402Phosphinic Acid

Product 1

HCID 137479Ethyl 3,4,5-trimethyl-1H-pyrrole-2-carboxylate

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

2,4-Dimethyl-5-carbethoxy-pyrrole (0.83 g), acetic acid (10 ml), hydriodic acid (10 ml) and paraformaldehyde (0.60 g) were stirred 3 hours at 25° C. under nitrogen. Hypophosphorous acid (50%, about 1 ml) was added, dropwise to decolourize the solution. The cooled solution (0° C.) was made basic with ammonium hydroxide and the product was extracted with ether (2 × 20 ml). The extract was dried over magnesium sulfate, filtered, and the ether removed in a rotating evaporator at 20° C. Recrystallization of the residue from benzene gave the product, 0.58 g (64%), m.p. 125°-126° C. (lit3 m.p. 126° C.).

Workup

  1. customThe cooled solution (0° C.)
  2. extractionthe product was extracted with ether (2 × 20 ml)
  3. dry with materialThe extract was dried over magnesium sulfate
  4. filtrationfiltered
  5. customthe ether removed in a rotating evaporator at 20° C
  6. customRecrystallization of the residue from benzene
  7. customgave the product, 0.58 g (64%), m.p. 125°-126° C. (lit3 m.p. 126° C.)

Sources & evidence

ORD record
ord-12261fb6ea3048ca83680a7ff794dcca
Source dataset
uspto-grants-1978_01
Patent number
US04070366

Reaction notes

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