US 12,264,135 B2
Synthesis of 1,4-diazaspiro[5.5]undecan-3-one
Stephen E. Schneider, Raleigh, NC (US); Hannah White, Chapel Hill, NC (US); Thomas Fessard, Basel (CH); and Sagar Beldar, Basel (CH)
Assigned to Pharmacosmos Holding A/S, Holbaek (DK)
Filed by Pharmacosmos Holding A/S, Holbaek (DK)
Filed on Jul. 24, 2023, as Appl. No. 18/225,537.
Application 18/225,537 is a continuation of application No. 17/184,354, filed on Feb. 24, 2021, granted, now 11,708,337.
Application 17/184,354 is a continuation of application No. PCT/US2019/048029, filed on Aug. 23, 2019.
Claims priority of provisional application 62/722,675, filed on Aug. 24, 2018.
Prior Publication US 2024/0199556 A1, Jun. 20, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. C07D 241/38 (2006.01); C07C 219/18 (2006.01); C07D 239/47 (2006.01)
CPC C07D 241/38 (2013.01) [C07C 219/18 (2013.01); C07D 239/47 (2013.01)] 18 Claims
 
1. A process to prepare a spirocyclic compound comprising:
a. reducing a compound of Formula III with a reducing agent;
b. cyclizing the compound of step (a);
wherein Formula III is:

OG Complex Work Unit Chemistry
wherein the spirocyclic compound is of Formula:

OG Complex Work Unit Chemistry
wherein
y is 0;
n is 0 or 1;
R1 is hydrogen;
R2 is hydrogen, substituted heteroaryl, or

OG Complex Work Unit Chemistry
R3 is hydrogen;
R4 is NR8R9 or OR10;
R8 and R9 are independently selected from the group consisting of hydrogen, alkyl, aryl, and -alkyl-aryl;
R10 is alkyl, aryl, or -alkyl-aryl;
R12 is alkyl, aryl, or -alkyl-aryl; and
R13 is —S-alkyl or Cl.