Setup routes for each device. Your laptop will probably use router1 as default route. From there router 1 needs an explicit route for the IP addresses on the intranet to router 2. Probably the return path from your intranet doesn't know the addresses from your own network, router 2 should act as a NAT towards the intranet.
IP routing is hop-by-hop, each device should know which next hop traffic to and from each network should be routed
Edit based on your updated picture:
Because the laptop is now in the same 192.168.1.0/24 network as your router 2, you can tell the laptop that everything routed to 43.6.20.0/24 should be routed to 192.168.1.1, the default is to use 192.168.1.2 for anything else. router 1 doesn't need to do any IP routing anymore, it just needs to act as a network switch. The explicit route was needed to route between 192.168.1.0/24 and 172.168.1.1 which I now realize was a typo. Your route in openwrt would have been almost correct, you would have to set the gateway. But if router 1 and 2 are in the same IP network, it's not relevant anymore
For IP routing what matters is that each hop can reach the next IP hop., each hop needs needs a router to the next neighbor. For you the laptop and router 2 are in the same IP network, so either on your laptop you have a route for 43.6.20.0/24 via router 2 or you send by default everything to router 1 and there route 43.6.20.0/24 via gateway 192.168.1.2
On router 2 you need a NAT to reach 43.6.20.0/24
On your laptop, you would need static routes like this.
route add 43.6.20.0/24 via 192.168.1.1
route add default via 192.168.1.2
the exact syntax between operating systems and network manager differ.
With explicit I meant that the route needed to be specified by yourself, because packets would otherwise by default sent to the wrong network branch. It's static because you don't use routing protocols to announce routes, hardly anybody does unless you have a bigger network.
