abstract |
(57) Abstract: A compound of the formula (IA) (sildenafyl) il) / Viagra® and the formula (I) Compound of B): Comprising the compounds of formula (IIA) and formula (IIB), respectively: The (wherein, X is a leaving group), - OR (wherein, R in the case of the compound (IA) produced is CH 2 CH 3, R in the case of the compound (IB) produced is CH 2 CH 2 CH 3 ). It utilizes safe (avoids the need to use carcinogenic alkylating reagents), economical, readily available starting materials, and allows for new displacement reactions in a single reaction vessel. It is a very good process for preparing compounds of formula (I) in combination with a ring closure reaction. |