You skipped move 2 :O. Play one of the mainlines, either with 4... Bc5 or 4... Nf6.
The scotch for black
In the recent Ultimate Blitz Challenge, Kasparov played the Scotch against Nakamura and Caruana and maybe So.
There are some video outakes on YouTube and maybe the original broadcasts and/or pgn's are still out there. Out of those games, I'd guess you'll probably find some defense that looks interesting.
Possibly helpful:
Beating the open games, Mihail Marin
https://web.archive.org/web/20140626195205/http://www.chesscafe.com/text/hansen102.pdf
Open-Games-Black-Igor-Lysyj
https://web.archive.org/web/20140627104938/http://www.chesscafe.com/text/hansen159.pdf
Play the Open Games as Black by John Emms
https://web.archive.org/web/20140627022601/http://www.chesscafe.com/text/hansen11.txt
Bologan's Black Weapons in the Open Games
http://www.jeremysilman.com/shop/pc/Bologans-Black-Weapons-in-the-Open-Games-76p3873.htm
Starting Out: Open Games by GM Glenn Flear (2010)
https://web.archive.org/web/20140626232452/http://www.chesscafe.com/text/hansen134.pdf
Play 1 e4 e5! by Nigel Davies (2006)
https://web.archive.org/web/20140626201436/http://www.chesscafe.com/text/hansen80.pdf
https://web.archive.org/web/20140627083715/http://www.chesscafe.com/text/hansen98.pdf
The Kaufman Repertoire for Black & White by Larry Kaufman (2012)
https://web.archive.org/web/20140626221508/http://www.chesscafe.com/text/hansen162.pdf
Opening Repertoire: The Open Games with Black by Martin Lokander (2015)
Playing 1.e4 e5 - A Classical Repertoire by Nikolaos Ntirlis (2016)
There are 46 pages on 1 e4 e5 2 Nf3 Nc6 3 d4 ed 4 Nxd4 Bc5 in Bologan's Black Weapons in the Open Games.
http://www.jeremysilman.com/shop/pc/Bologans-Black-Weapons-in-the-Open-Games-76p3873.htm
About 13 pages in Starting Out: Open Games by GM Glenn Flear (2010).
https://web.archive.org/web/20140626232452/http://www.chesscafe.com/text/hansen134.pdf
Hi, I am looking for a defence against the scotch(1e4,e5 2.Nf3,Nc6 3.d4).Suggestions?