Phosphoric Acid → methyl 5-(4-chlorophenyl)-6-cyclohex-1-en-1-yl-4H-thieno[3,2-b]pyrrole-2-carboxylate

HRID 505794Notes

Reaction equation

[Cl:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[NH:12][C:11]3[CH:13]=[C:14]([C:16]([O:18][CH3:19])=[O:17])[S:15][C:10]=3[CH:9]=2)=[CH:4][CH:3]=1.C(OC(=O)C)(=O)C.[C:27]1(=O)[CH2:32][CH2:31][CH2:30][CH2:29][CH2:28]1.P(=O)(O)(O)O>C(O)(=O)C>[Cl:1][C:2]1[CH:3]=[CH:4][C:5]([C:8]2[NH:12][C:11]3[CH:13]=[C:14]([C:16]([O:18][CH3:19])=[O:17])[S:15][C:10]=3[C:9]=2[C:27]2[CH2:32][CH2:31][CH2:30][CH2:29][CH:28]=2)=[CH:6][CH:7]=1

Participants

Conditions

Temperature: 80 °C

Procedure

A solution (0.2 M) of methyl 5-(4-chlorophenyl)-4H-thieno[3,2-b]pyrrole-2-carboxylate in acetic acid was treated with acetic anhydride (2.5 eq.), cyclohexanone (10 eq.) and 85% phosphoric acid (2.1 eq.). The mixture was heated at 80° C. for 3.5 days. After cooling down it was poured into ice cold ammonium hydroxide. The product was extracted with AcOEt and the combined organic layers were washed sequentially with aqueous HCl (1 N), aqueous NaHCO, (saturated solution) and brine then dried and concentrated. The crude was purified by flash chromatography on silica gel (1:9 to 1:4 AcOEt/petroleum ether) affording the title compound (91%) as a solid.

Workup

temperatureAfter cooling down it
additionwas poured into ice cold ammonium hydroxide
extractionThe product was extracted with AcOEt
washthe combined organic layers were washed sequentially with aqueous HCl (1 N), aqueous NaHCO, (saturated solution) and brine
customthen dried
concentrationconcentrated
customThe crude was purified by flash chromatography on silica gel (1:9 to 1:4 AcOEt/petroleum ether)

Sources & evidence

ORD record: ord-a441f15e86f544f48defa17382110b55
Source dataset: uspto-grants-2010_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07781431B2

Reaction notes

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