At the beginning of the experiment, the model reaction of
N-phenyl-
N-(prop-2-yn-1-yl)methacrylamide (
1a) with 4-methoxyphenylazo mesylate (
2a) was chosen to test the optimized reaction conditions. The product
3a was only isolated in 6% yield when the model reaction was conducted in 1, 4-dioxane at 80 ℃(
Table 1, entry 1). To our delight, the yield of
3a was largely increased when water was added in this reaction system (
Table 1, entries 2–6). The highest yield of
3a (70%) was obtained when the ratio of 1, 4-dioxane and water was 2:1 (
Table 1, entry 6). The yield would be slightly decreased if we continued to increase the amount of water (
Table 1, entry 7). Next, various mixed solvents with organic solvent and water (2/1) were investigated (
Table 1, entries 8–15). Generally, low to moderate yields were observed when the reaction was carried out in the mixture of EtOH, DME, THF, DMF, DMSO, or DCE with H
2O (2/1). Only a trace amount of product
3a was detected when the reaction was performed in CH
2Cl
2/H
2O (2/1). None of the product was observed in CH
3CN/H
2O (
Table 1, entry 15). The decrease of reaction temperature would lead to lower reaction efficiency. No transformation was observed when the reaction was conducted at room temperature (
Table 1, entry 17). The reaction was not improved when the reaction temperature was increased to 90 ℃ (
Table 1, entry 18). Furthermore, product
3a was still obtained in good yield when the reaction was carried out under nitrogen atmosphere (
Table 1, entry 19). Moreover, the use of other arylazo mesylates (4-methylphenylazo mesylate, 4-fluorophenylazo mesylate or 4-chlorophenylazo mesylate) to replace 4-methoxyphenylazo mesylate also gave the desired product
3a, but lower reaction efficiency was observed (
Table 1, entries 20–22). Moreover, when the reaction was carried out under irradiation with 3 W Blue LED lamps, the corresponding product
3a was obtained in 22% yield (
Table 1, entry 23).