A method produces a 3,4-dihydro-1,2,3-oxathiazin-4-one-2,2-dioxide compound of following formula (2):
wherein R
1
and R
2
are the same as or different from each other and are each hydrogen atom or an organic group inert to the reaction; and R
3
is hydrogen atom or an organic group inert to the reaction, or a salt thereof, by subjecting a beta-ketoamide-N-sulfonic acid of following Formula (1):
wherein R
1
, R
2
and R
3
are as defined above; and X is hydrogen atom, or a salt thereof, to cyclization in the presence of an acid anhydride with or without further subjecting the cyclized product to hydrolysis, in which the cyclization is continuously carried out using a continuous flow reactor.
                            一种方法通过在连续流反应器中将以下式子(1)中的β-酮酰胺-N-
磺酸与酸酐在存在或不存在
水解的情况下环化,制备出下式(2)的3,4-二氢-1,2,3-噁嗪-4-酮-2,2-二氧化物化合物:其中R1和R2相同或不同,均为氢原子或对反应不活泼的有机基团;R3为氢原子或对反应不活泼的有机基团或其盐。其中,X为氢原子或其盐。