p-Methoxyphenylthionophosphine sulfide → 7-Chloro-6-pyridin-3-yl-8-thiocarbamoyl-3,4-dihydro-1H-pyrrolo[1,2-a]pyrazine-2-carboxylic acid tert-butyl ester

Participants

Reaction Conditions

Reaction Steps

A stirred suspension of 8-carbamoyl-7-chloro-6-pyridin-3-yl-3,4-dihydro-1H-pyrrolo[1,2-a]pyrazine-2-carboxylic acid tert-butyl ester (486 mg, Reference Example 2b) in toluene (25 mL) was treated with 4-methoxyphenylthionophosphine sulfide dimer (513 mg). After stirring at 80° C. for 2 hours the reaction mixture was allowed to cool to room temperature and then evaporated. The residue was subjected to column chromatography on silica eluting with dichloromethane, then with a mixture of methanol and dichloromethane (1:99, v/v) and then with a mixture of methanol and dichloromethane (1:49, v/v) to give the title compound (129 mg) as a off white solid, m.p. 220–221° C. [Elemental Analysis: C, 54.79; H, 5.10; N, 13.86%. Calculated for C18H21ClN4O2S: C, 55.03; H, 5.39; N, 14.26%].

Provenance & Evidence