AMENDMENT NO. 1 TO AGREEMENT AND PLAN OF MERGER

Exhibit 2.1

AMENDMENT NO. 1 TO AGREEMENT AND PLAN OF MERGER

This AMENDMENT NO. 1, dated as of December 23, 2014 (this “Amendment”), to the Agreement and Plan of Merger, dated as of October 17, 2014 (the “Reorg Merger Agreement”), is made by and among Walgreen Co., an Illinois corporation (the “Company”), Ontario Merger Sub, Inc., an Illinois corporation and indirect wholly owned subsidiary of the Company and direct wholly owned subsidiary of HoldCo (“Merger Sub”) (the Company and Merger Sub, when referred to individually, each a “Constituent Corporation” and when referred to collectively, “Constituent Corporations”), and Walgreens Boots Alliance, Inc., a Delaware corporation and a direct wholly owned subsidiary of the Company (“HoldCo”).

WITNESSETH:

WHEREAS, the Company, Merger Sub, and HoldCo have entered into the Reorg Merger Agreement; and

WHEREAS, subject to the terms and conditions set forth in this Amendment, and pursuant to Section 7.01 of the Reorg Merger Agreement, the Company, Merger Sub, and HoldCo desire to amend certain terms of the Reorg Merger Agreement by entering into, and as set forth in, this Amendment.

NOW, THEREFORE, in consideration of the representations, warranties, covenants and agreements contained in this Agreement, the parties have agreed as follows:

1. Modification; Full Force and Effect. Except as expressly modified and superseded by this Amendment, the terms and provisions of the Reorg Merger Agreement are and shall continue to be in full force and effect.

2. Definitions. Capitalized terms used herein without definition shall have the meanings ascribed to such terms in the Reorg Merger Agreement unless otherwise indicated.

3. Modifications to the Reorg Merger Agreement.

(a) Effectively immediately, the second sentence of Section 1.02 of the Reorg Merger Agreement is hereby amended and restated in its entirety to read as follows:

The Reorg Merger shall become effective at 12:01 a.m. Central Standard Time on December 31, 2014, subject to the due filing of Articles of Merger with the Secretary of State (such date and time, the “Effective Time”).

(b) Effectively immediately, Section 1.01(c) of the Reorg Merger Agreement is hereby amended and restated in its entirety to read as follows:

Company Common Stock. At the Effective Time, each share or fraction of a share of common stock of the Company, par value $0.078125 per share (the “Company Common Stock”), issued and outstanding immediately prior to the Effective Time,

(c) Effective immediately, Section 2.01 of the Reorg Merger Agreement is hereby amended and restated in its entirety to read as follows:

Articles of Incorporation and Bylaws of Surviving Company. The articles of incorporation and bylaws of the Company, as in effect immediately prior to the Effective Time, shall remain in effect as the articles of incorporation and bylaws of the Surviving Company until thereafter amended in accordance with applicable law and the applicable provisions of the articles of incorporation and bylaws.

and each share of Company Common Stock owned by the Company as treasury stock, shall be converted into and exchanged for one fully paid and nonassessable share (or an equivalent fraction of a share) of common stock, par value $0.01 per share, of HoldCo (the “HoldCo Common Stock”).

4. Miscellaneous. The provisions of Article VIII of the Reorg Merger Agreement shall apply mutatis mutandis to this Amendment.

[signature page follows]

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IN WITNESS WHEREOF, this Amendment is hereby executed on behalf of each Constituent Corporation and on behalf of HoldCo by a duly authorized officer thereof as of the date specified above.

[Signature Page to Amendment No. 1 to Agreement and Plan of Merger]