	US 11,939,280 B2
	Method for preparing isophorone diisocyanate
Yong Yu, Shandong (CN); Yonghua Shang, Shandong (CN); Lei Zhao, Shandong (CN); Wenbin Li, Shandong (CN); Ye Sun, Shandong (CN); Wei He, Shandong (CN); Xuelei Cui, Shandong (CN); Jingxu Wang, Shandong (CN); Degang Liu, Shandong (CN); and Yuan Li, Shandong (CN)
Assigned to WANHUA CHEMICAL GROUP CO., LTD., Shandong (CN)
Appl. No. 17/295,369
Filed by WANHUA CHEMICAL GROUP CO., LTD., Shandong (CN)
PCT Filed Dec. 25, 2018, PCT No. PCT/CN2018/123444 § 371(c)(1), (2) Date May 19, 2021, PCT Pub. No. WO2020/124622, PCT Pub. Date Jun. 25, 2020.
Claims priority of application No. 201811567103.0 (CN), filed on Dec. 20, 2018.
Prior Publication US 2022/0002235 A1, Jan. 6, 2022
Int. Cl. C07D 263/10 (2006.01); B01J 25/00 (2006.01); C07C 209/48 (2006.01); C07C 253/10 (2006.01); C07C 263/10 (2006.01)

CPC C07C 263/10 (2013.01) [B01J 25/00 (2013.01); C07C 209/48 (2013.01); C07C 253/10 (2013.01); C07C 2601/16 (2017.05)]

20 Claims

1. A method for preparing isophorone diisocyanate, comprising the following steps:

(1) reacting isophorone with hydrogen cyanide in the presence of a catalyst to obtain isophorone nitrile;

(2) reacting the isophorone nitrile obtained in step (1) with ammonia gas and hydrogen in the presence of a catalyst to obtain isophorone diamine; and

(3) subjecting the isophorone diamine to a phosgenation reaction to obtain isophorone diisocyanate,

wherein the content of impurities containing a secondary amine group in the isophorone diamine that is subjected to the phosgenation reaction in step (3) is less than or equal to 0.5 wt %.