US 10,888,561 B2
CGRP receptor antagonists
John Andrew Christopher, Cambridge (GB); Miles Stuart Congreve, Cambridge (GB); Sarah Joanne Bucknell, Cambridge (GB); Francesca Deflorian, Cambridge (GB); Mark Pickworth, Cambridge (GB); and Jonathan Stephen Mason, Cambridge (GB)
Assigned to Heptares Therapeutics Limited, Cambridge (GB)
Filed by Heptares Therapeutics Limited, Cambridge (GB)
Filed on Apr. 8, 2019, as Appl. No. 16/377,519.
Application 15/713,775 is a division of application No. 15/336,866, filed on Oct. 28, 2016, granted, now 9,808,457, issued on Nov. 7, 2017.
Application 16/377,519 is a continuation of application No. 15/713,775, filed on Sep. 25, 2017, granted, now 10,300,056.
Claims priority of application No. 1519196.8 (GB), filed on Oct. 30, 2015.
Prior Publication US 2019/0231773 A1, Aug. 1, 2019
This patent is subject to a terminal disclaimer.
Int. Cl. A61K 31/496 (2006.01); C07D 401/14 (2006.01); C07D 498/10 (2006.01); C07D 241/14 (2006.01); C07D 471/04 (2006.01); C07D 498/20 (2006.01)
CPC A61K 31/496 (2013.01) [C07D 241/14 (2013.01); C07D 401/14 (2013.01); C07D 471/04 (2013.01); C07D 498/10 (2013.01); C07D 498/20 (2013.01)] 10 Claims
1. A compound of formula (I)

OG Complex Work Unit Drawing
or a salt thereof, wherein R1 is H or Q-(C1-C6)alkyl; where Q is a bond, C(O) or C(O)O and where the (C1-C6)alkyl can be optionally substituted by N(C1-C3alkyl)2 or CO2H;
R2 is H or forms a spirocyclic heterocyclic ring with R3;
R3 forms a spirocyclic heterocyclic ring with R2 or is a heterocyclic ring if R2 is H; and
R4 is an optionally substituted aryl group which is fused to a further ring.