The reaction of a wide number of benzaldehydes (1a-n) with ethyl (2a) or methyl (2b) acetoacetate and aqueous ammonia (3) has been carried out in the absence of an organic solvent, and using for the first time infrared irradiation as the heating mode. Thus, under the green chemistry protocole, the corresponding mono-1,4-dihydropyridines (4a-j) and bis-1,4-dihydropyridines (4k-n) were obtained in good yields and short reaction times.

En este trabajo se presentan y discuten los resultados obtenidos de la reacción entre varios banzaldehídos (1a-n) con acetoacetato de etilo (2 a) o metilo (2b) e hidróxido de amonio (3); lo anterior mediante el protocolo de la química verde: ausencia de disolvente orgánico y empleando irradiación infrarroja como fuente de activación. De esta manera se obtuvieron las correspondientes mono-1,4-dihidropiridinas (4a-j) y bis-1,4-dihidropiridinas (4k-n) con buenos rendimientos y en tiempos cortos de reacción.

The insecticidal activity and residual effect of two formulations of lambdacyhalothrin were evaluated with Rhodnius prolixus;laboratory and field tests were conducted in the State of Chiapas, Mexico. The results indicate that the lethal concentrations of the active ingredient of SC (LC50 = 2.37 and LC90 = 8.5 mg, a.i./m²) were 4-8 times than those with the insecticide WP applied on R. prolixus bugs in palm leaves, a common building material for thatched roofs. Other investigators in South America recommended applying 30 mg a.i./m² in porous materials; we obtained that the products WP and SC were 3.5 and 16 times more effective on palm leaves. Regarding the evaluation of the residual effects in field spraying, there was up to 15 months persistence after the application of WP in two doses (8.6 mg a.i./m² and 3.752 mg a.i./m²) with SC. We consider R. prolixus highly susceptible to the employed pyrethroids; they could be used to control this vector in the state of Chiapas, Mexico.