| abstract |
The invention relates to a method for producing a compound of formula (IA) (sildenafil / Viagra ™) and (IB) comprising reacting a compound of formula (IIA) and (IIB), respectively, in the presence of OR, where R, in the case of formation of (IA), is CHCH and R, in the case of the formation of compound (IB), it represents an SNCHCH, where X represents a leaving group, provided that X is not ethoxy The invention also relates to new intermediates for the synthesis of compounds of formula (IA) and (IB) - compounds of general formulas (II) and ( IIB); general formulas (IIIA) and (IIIB) and general formulas (VIIA) and (VIIB) where X is selected from halogen or methoxy. |