US 12,129,239 B2
Method for producing methylene disulfonate compound
Seiya Ashibe, Hyogo (JP); Seiji Bando, Hyogo (JP); and Yusaku Masuhara, Hyogo (JP)
Assigned to SUMITOMO SEIKA CHEMICALS CO., LTD., Hyogo (JP)
Appl. No. 17/629,167
Filed by SUMITOMO SEIKA CHEMICALS CO., LTD., Hyogo (JP)
PCT Filed Jul. 22, 2020, PCT No. PCT/JP2020/028366
§ 371(c)(1), (2) Date Jan. 21, 2022,
PCT Pub. No. WO2021/015219, PCT Pub. Date Jan. 28, 2021.
Claims priority of application No. 2019-135408 (JP), filed on Jul. 23, 2019.
Prior Publication US 2022/0251059 A1, Aug. 11, 2022
Int. Cl. C07D 327/00 (2006.01)
CPC C07D 327/00 (2013.01) 5 Claims
 
1. A method for producing a methylene disulfonate compound, the method comprising reacting at least one sulfonic acid compound with a formaldehyde compound in the presence of sulfur trioxide,
the amount of sulfur trioxide being 2.0 to 10 moles per 1.0 mole of the sulfonic acid compound,
the sulfonic acid compound being selected from the group consisting of:
compounds represented by formula (1):

OG Complex Work Unit Chemistry
wherein two Xs are the same or different and represent a hydrogen atom or an alkali metal;
R1 and R2 are the same or different and represent a C1-4 alkyl group optionally substituted with one or more halogen atoms or a hydrogen atom;
n is an integer of 1 to 4;
when n is an integer of 2 to 4, n R1s may be the same or different and n R2s may be the same or different; and
compounds represented by formula (2):

OG Complex Work Unit Chemistry
wherein Y represents an alkaline earth metal, and R1, R2, and n are as defined above, and the methylene disulfonate compound being represented by formula (3):

OG Complex Work Unit Chemistry
wherein R1, R2, and n are as defined above.