Hydrogen Bromide → HCID 15499896, compound

HRID 1757592Notes

Reaction equation

HRID 1757592 reaction equation
[C:1]1([C:7]2[C:11]([CH2:12][CH3:13])=[C:10]([CH3:14])[NH:9][C:8]=2[C:15]([O:17][CH2:18][CH3:19])=[O:16])[CH:6]=[CH:5][CH:4]=[CH:3][CH:2]=1.Br>C(O)=O>[C:1]1([C:7]2[C:11]([C:12]3[CH:3]=[CH:2][CH:1]=[CH:6][CH:13]=3)=[C:10]([CH3:14])[NH:9][C:8]=2[C:15]([O:17][CH2:18][CH3:19])=[O:16])[CH:2]=[CH:3][CH:4]=[CH:5][CH:6]=1

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 13863060HCID 13863060, compound

Product 1

HCID 15499896HCID 15499896, compound

Reagents, catalysts & solvents 1

HCID 284Formic AcidSolvent

Conditions

Temperature
100 °C

Procedure

Pyrromethene Hydrobromides and BF2Complexes. Crude pyrromethene hydrobromides 6 were obtained from a α-pyrrole carboxylate esters 4 (Kleinspehn, 1955) and converted without purification to P-BF2 dyes 7. A mixture of ethyl 3-phenyl-4-ethyl-5-methylpyrrole-2-carboxylate 40 (2.57 g, 10 mmol), hydrobromic acid (3 ml, 48%) and formic acid (3.5 g) was heated at 100° C. for 4 h. The reaction mixture was cooled to 0° C. to bring about the separation of crude 3,3'-diphenyl-4,4'-diethyl-5,5'-dimethylpyrromethene hydrobromide 6u 1.3 g(55%) mp 235° C. (dec); ethyl 3,4-diphenyl-5-methyl-pyrrole-2-carboxylate 4p gave crude 3,4,3',4'-tetraphenyl-5,5-dimethylpyrromethene hydrobromide 6v (75%) mp 280° C. (dec) (lit. mp 280° C. (dec)); and ethyl 3-phenyl-4-acetyl-5-methylpyrrole-2-carboxylate 4q gave crude 3,3'-diphenyl-4,4'-diacetyl-5,5'-dimethylpyrromethene hydrobromide 14 (50%) mp 230° C. (dec). In similar conversions 3,5-dimethyl-4-tert-butylpyrrole-2-carboxylate 4g gave crude 3,5,3',5'-tetramethyl-2,6-di-tert-butylpyrromethene hydrobromide 6x and ethyl 3,4-diethyl-5-methylpyrrole-2-carboxylate 4k gave crude 3,4,3',4'-tetraethyl-5,5'-dimethylpyrromethene hydrobromide 6y.

Workup

  1. customconverted without purification to P-BF2 dyes 7
  2. temperatureThe reaction mixture was cooled to 0° C.
  3. customto bring about the separation of crude 3,3'-diphenyl-4,4'-diethyl-5,5'-dimethylpyrromethene hydrobromide 6u 1.3 g(55%) mp 235° C. (dec)

Sources & evidence

ORD record
ord-fb8286f7039f4dd7ae9f6fad51cbf17e
Source dataset
uspto-grants-1995_08
Patent number
US05446157

Reaction notes

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