. 2021 Sep 16;86(19):13817–13823. doi: 10.1021/acs.joc.1c01888

Table 1. Optimization of the Reaction Conditions.

entry	equiv	T (°C)	solvent	time (h)	conversion (%)^a
1	4	rt	MeOH	24	27^c
2	8	rt	MeOH	24	60
3	10	rt	MeOH	24	>99
4	4	50	MeOH	12	>99 (91)^b
5	2	50	MeOH	12	45^c
6	3	50	MeOH	12	73^c
7	4	50	EtOH	12	>99
8	4	50	CH₂Cl₂	24
9	4	50	toluene	24
10	4	rt	CH₃CN	2	>99 (93)^b
11	2	rt	CH₃CN	2	>99 (90)^b
12	2	rt	DMF	12

Determined by ¹H NMR in the crude reaction mixture.

Yield after chromatographic purification.

Nitrone is the only observed product in the ¹H NMR spectra.