	US 12,084,402 B2
	Preparation process of diazomethane
Hao Hong, Morrisville, NC (US); Jiangping Lu, Tianjin (CN); Enxuan Zhang, Tianjin (CN); Wei Shen, Tianjin (CN); Honglei Yan, Tianjin (CN); and Zhen Zhang, Tianjin (CN)
Assigned to ASYMCHEM LABORATORIES (TIANJIN) CO., LTD., Tianjin (CN)
Appl. No. 17/611,712
Filed by ASYMCHEM LABORATORIES (TIANJIN) CO., LTD., Tianjin (CN)
PCT Filed May 21, 2019, PCT No. PCT/CN2019/087761 § 371(c)(1), (2) Date Nov. 16, 2021, PCT Pub. No. WO2020/232625, PCT Pub. Date Nov. 26, 2020.
Prior Publication US 2022/0242818 A1, Aug. 4, 2022
Int. Cl. C07C 245/16 (2006.01)

CPC C07C 245/16 (2013.01)

17 Claims

1. A preparation process of diazomethane, comprising:

step S1, continuously feeding an acid, a solvent, a sodium nitrite and N-methylurea to the continuous reactor for reaction to prepare a first product system containing N-methyl-N-nitrosourea;

step S2, performing continuous extraction and continuous back-extraction on the first product system to obtain an N-methyl-N-nitrosourea solution;

step S3, enabling the N-methyl-N-nitrosourea solution to continuously react with an alkaline solution in a continuous reactor to obtain a second product system containing the diazomethane; and

step S4, performing continuously liquid separation, water freezing and removal on the second product system, to obtain the diazomethane.