[c-nsp] route leak from main to vrf

[BASSAGET Cédric]

Hello,
I'm trying to leak routes from my main routing table to a VRF.

Using Cisco IOS XE Software, Version 16.09.05 on a ASR1001-X

I've done this config :

ip prefix-list BT_LNS-out seq 5 permit x.x.x.3/32
ip prefix-list BT_LNS-out seq 10 permit x.x.x.4/32

ip prefix-list BT_radius-out seq 5 permit x.x.x.5/32
ip prefix-list BT_radius-out seq 10 permit x.x.x.6/32

route-map BT_bgp-out permit 10
 match ip address prefix-list BT_LNS-out BT_radius-out

ip vrf interco_BT
 rd 12844:1
 import ipv4 unicast map BT_bgp-out

ip route x.x.x.3 255.255.255.255 Loopback0
ip route x.x.x.4 255.255.255.255 <next-hop>
ip route x.x.x.5 255.255.255.255 <next-hop>
ip route x.x.x.6 255.255.255.255 <next-hop>

so my main routing table has routes to x.x.x.[3-6]/32 but I'm unable to see
the routes in the VRF "interco_BT".

Tried to add route in the vrf :
ip route vrf interco_BT x.x.x.3 255.255.255.255 loopback 0
% For VPN or topology routes, must specify a next hop IP address if not a
point-to-point interface

I guess I'm missing something.
Can somebody tell my where I am wrong please ?

Thank you.
Regards,
Cédric