DEERFIELD, Ill. — Walgreen Co. has agreed to buy 12 Eaton Apothecary pharmacies in the Boston area from D.A.W. Inc. for about $19 million.

The deal is slated to close within 90 days, according to Walgreens.

“Today is a very special day for our Boston market,” says Dave White, Walgreens market vice president for Boston. “Not only are we keeping most of the pharmacies open, but we also intend for eligible employees at all 12 locations to join our team. Eaton’s customers should expect to see the familiar faces and services they know and trust, while benefiting from Walgreens’ expanded product and service offering. We look forward to continuing Eaton’s 100-plus-year tradition of quality pharmacy service in communities around the Boston area.”

Mark Dumouchel, president of Eaton’s owner, D.A.W., a subsidiary of Nyer Medical Group Inc., says, “I am happy to say that Walgreens’ interest in Eaton’s has been beyond buying only prescription files — they will continue to operate a majority of the 12 stores as well as hire all eligible employees from the 12 locations.”

Walgreens has said that much of its future expansion will take place in the Northeast and in California. The chain opened its 7,000th store earlier this month in Brooklyn, N.Y., and overall it expects to open about 300 stores annually in each of the next few years.