57024-76-7Relevant academic research and scientific papers
A short and efficient synthetic protocol for the synthesis of 5-substituted-4,6-dioxo-pyrrolo[2,3-d]pyrimidines
Sekhar,Acharyulu, Palle V.R.,Anjaneyulu, Yerramilli
experimental part, p. 4140 - 4144 (2011/09/19)
A short and efficient synthesis for 5-substituted-4,6-dioxo-pyrrolo[2,3-d] pyrimidines has been developed by the cyclocondensation of α,α- dibromoaldehydes with 2,4-diamino-6-hydroxypyrimidine under mild basic conditions in good yields. Application of this protocol has been demonstrated in the synthesis of a metabolite of Pemetrexed disodium, a novel multi-targeted antifolate.
Preparation de sels d'iminiums α,α-dihalogenes. Reaction avec quelques reactifs nucleophiles
Poirier, Jean-Marie
, p. 17 - 22 (2007/10/02)
β-Haloenamines 1 react easily with halogens (chlorine or bromine) to give α,α-dihaloiminium salts 2.These compounds can also be prepared from non-halogenated enamines 3 by a one-pot reaction.Iminium salts 2 are very rapidly hydrolized to α,α-dihalocarbonyl compounds 4.This reaction is a convenient preparation method of α,α-dichloroaldehydes; this synthetic way is also efficient, when a non-conjugated double bond is present in the alkyl group of salts 2.With iminium salts 2, alcohols and secondary amines give respectively the addition compounds 5 and 9; primary amines yield α,α-dihaloimines 10.Two possible ways are observed for the reaction of Grignard reagents (R1MgX) with dichloroiminium salts: addition - path A - (R1=Me, Et) or reduction - path B - (R1=tBu, iPr).The reduction reaction is favoured when the Grignard reagent is hindered.Addition and reduction are in competition with R1=nPr.When one of the halogens of salt 2 is bromine, a β-haloenamine is produced.
