According to exclusive reports from Goal, the Gunners - who have been linked frequently with the 25-year-old in recent weeks along with the likes of Liverpool and Manchester United - have agreed on a price of £32 million with his current employers and will look to complete the deal soon.
The same speculation suggests that Sanchez and his representatives have already provisionally agreed to the financial terms on offer, with Arsene Wenger supposedly believing that the former Udinese star can be molded into an elite centre-forward at the Emirates Stadium.
Arsenal are certainly in need of making immediate additions to their options in the final third, with Olivier Giroud and young Yaya Sanogo currently the only real recognised strikers - unless you count Lukas Podolski, who has experience of playing as an out-and-out frontman - in Wenger's squad.
While Sanchez has played as a forward in La Liga and indeed at international level, he has also spent a lot of time out on the flank, where his electric pace and dazzling trickery can prove torturous for opposition full-backs.
Arsenal fans may be forgiven for having reservations of Sanchez's ability to lead the line on his own, yet Wenger has history in this particular department and most-famously converted the legendary figure of Thierry Henry into a fearsome striker following his arrival in North London from Juventus in 1999.
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Sanchez appeared eager to remain at the Camp Nou in spite of all the recent transfer speculation, yet it appears he may now have accepted that he will need to move on as Barcelona head in a slightly different direction under the tutelage of new manager Luis Enrique.
The Catalan's relentless pursuit of controversial Liverpool talisman Luis Suarez led many to believe that Sanchez was likely to be heading to Anfield as part of a possible deal for the Uruguayan, yet that appears increasingly unlikely with the player himself understood to hold a preference for a move to Arsenal.
Now it appears as if Sanchez - who performed admirably for his country at the World Cup in Brazil before they suffered a heartbreaking penalty shootout exit to the hosts in their round of 16 clash - is about to get his wish, although it could well be that the deal is not confirmed until Barcelona have completed their pursuit of Suarez.
Manchester United's hopes of landing Sanchez appeared rather remote from the outset, meanwhile, and it would now appear that Louis van Gaal will need to switch his attentions elsewhere with the likes of James Rodriguez and William Carvalho believed to be among his top targets.