H. Uno et al., REACTION OF 2-NITROENAMINES AND 2-NITROALKENYL SULFIDES WITH ETHYL ISOCYANOACETATE - A NOVEL SYNTHESIS OF 1-HYDROXYPYRAZOLES, Journal of chemical research. Synopses, (2), 1996, pp. 76
The reaction of 2-nitroalkenyl sulfides 2 and 2-nitroenamines 3 with e
thyl isocyanoacetate in the presence of 1,8-diazabicyclo[5.4.0]undec-7
-ene gives ethyl 1-hydroxypyrazole-3-carboxylates 4 in moderate to goo
d yields.