Procedure for the obtaining of 1,2 - dihydro - pyrid (2,3 - d) pyrimidin - 2 onas. (Machine-translation by Google Translate, not legally binding)

摘要

Procedure for obtaining 1,2-dihydro-pyrido- [2,3-d] pyridin-2-one, of formula Ic, **(See formula)** where R means a hydrogen atom or an alkyl radical of 1 to 5 carbon atoms, R1 means an alkyl radical of 1 to 6 carbon atoms, other than a third alkyl group in which the third carbon atom is directly linked to the nitrogen atom of the ring, a 3- to 6-membered cycloalkyl radical in the ring, or the allyl, metalyl, or propargyl radical, and R2 means the phenyl radical or m substituted phenyl radical of formula II, **(See formula)** where Y means a fluorine, chlorine or bromine atom, or an alkyl or alkoxy radical of 1 to 4 carbon atoms, and Y1 means a hydrogen, fluorine, chlorine or bromine atom, or an alkyl or alkoxy radical of 1 to 4 carbon atoms, characterized by that a compound of formula VI is reacted, **(See formula)** wherein R, R'1 and R'2 have the meanings indicated above, with compound selected from the group consisting of (i) a C1-5 alkyl carbonate, preferably urethanes, (ii) urea, preferably at a temperature of 180ºC at 210ºC, (iii) isocyanic acid, preferably formed in situ using sodium or potassium isocyanate in the presence of a lower carboxylic acid and conveniently at a temperature of 100º to 140ºC, with the proviso that when an D1- alkyl carbamate is used 5 the reaction is carried out at a temperature of at least 140ºC, preferably at a temperature of 160ºC to 180ºC, and in the presence of a catalytic amount of a Lewis acid. (Machine-translation by Google Translate, not legally binding)