Sulfuric Acid → ethyl 4-(tert-butyl)-3,5-dimethyl-1H-pyrrole-2-carboxylate

HRID 1757588Notes

Reaction equation

HRID 1757588 reaction equation
S(=O)(=O)(O)O.[CH3:6][C:7]1[CH:11]=[C:10]([CH3:12])[NH:9][C:8]=1[C:13]([O:15][CH2:16][CH3:17])=[O:14].C(O[C:22]([CH3:25])([CH3:24])[CH3:23])(=O)C>C(O)(=O)C>[CH3:6][C:7]1[C:11]([C:22]([CH3:25])([CH3:24])[CH3:23])=[C:10]([CH3:12])[NH:9][C:8]=1[C:13]([O:15][CH2:16][CH3:17])=[O:14]

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 10908tert-Butyl acetateHCID 1374771H-Pyrrole-2-carboxylic acid, 3,5-dimethyl-, ethyl ester

Product 1

HCID 12039805ethyl 4-(tert-butyl)-3,5-dimethyl-1H-pyrrole-2-carboxylate

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

A solution of acetic acid (5.0 ml), sulfuric acid (1.2 ml), ethyl 3,5-dimethylpyrrole-2-carboxylate 5a (5.0 g, 0.03 mol) and tert-butyl acetate (3.5 g, 0.03 mol) was heated at 75° C. for 2 h and combinedwith sodium carbonate (8 g) in ice water (100 ml) to bring about the precipitation of ethyl 3,5-dimethyl-4-tert-butylpyrrole-2-carboxylate 4g as a colorless solid, mp 108°-110° C. (lit. 107°-109° C.), 3.1 g (47%); 1H NMR (CDCl3): δ 9.80 (s, 1H), 4.28 (q, 2H), 2.43 (s, 3H), 2.39 (s, 3H), 1.35 (s, 9H), 1.33 (t, 3H).

Workup

  1. customcombinedwith sodium carbonate (8 g) in ice water (100 ml) to bring about the precipitation of ethyl 3,5-dimethyl-4-tert-butylpyrrole-2-carboxylate 4g as a colorless solid, mp 108°-110° C. (lit. 107°-109° C.), 3.1 g (47%)

Sources & evidence

ORD record
ord-ba330ae5a6864d2dba43171313fe2e31
Source dataset
uspto-grants-1995_08
Patent number
US05446157

Reaction notes

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