Triethylamine → 7-Chloro-6-phenyl-2-(thiophene-2-sulfonyl)-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-8-carboxylic acid amide

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Reaction Conditions

Reaction Steps

A suspension of 7-chloro-6-phenyl-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-8-carboxylic acid amide trifluoroacetic acid salt (100 mg, Reference Example 1) in dry acetonitrile (15 mL) was treated with dry triethylamine (0.11 mL), then with 2-thiophenesulfonyl chloride (52 mg). After stirring at 60° C. for 7 hours the reaction mixture was allowed to cool to room temperature and then stand overnight. The solvent was removed under reduced pressure and the residue then treated with water and dichloromethane. The organic phase was separated, then dried over magnesium sulfate and evaporated. The residue was subjected to column chromatography on silica eluting with a mixture of methanol and dichloromethane (1:19, v/v) to give 7-chloro-6-phenyl-2-(thiophene-2-sulfonyl)-1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazine-8-carboxylic acid amide (100 mg) as a white solid, m.p. 240–242° C. [Elemental analysis: C, 50.95; H, 4.06; N, 9.98%; Calculated for C18H16ClN3O3S2: C, 51.24; H, 3.82; N, 9.96%].

Provenance & Evidence