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                                                                   EXHIBIT 10.12


                           MEMORY PHARMACEUTICALS,INC.
                           C/O WALTER GILBERT, PH.D.
                                 BIOLOGICAL LABS
                               HARVARD UNIVERSITY
                               17 DIVINITY AVENUE
                              CAMBRIDGE, MA 02138

                                                           As of January 5, 1998

Dr. Axel Unterbeck
205 Wildwood
Madison, CT 06443

         Re: Employment Agreement

Dear Dr. Unterbeck:

         This letter is to confirm our understanding with respect to (i) your
employment by Memory Pharmaceuticals, Inc. (the "Company"), (ii) your agreement
not to compete with the Company and (iii) your agreement to protect and preserve
information and property which is confidential and proprietary to the Company
(the terms and conditions agreed to in this letter shall hereinafter be referred
to as the "Agreement"). In consideration of the mutual promises and covenants
contained in this Agreement, and for other good and valuable consideration, the
receipt and sufficiency of which are hereby mutually acknowledged, we have
agreed as follows:

         1. Employment: Board of Directors. The Company will employ you, and you
agree to be employed by the Company, as President and Chief Scientific Officer
of the Company, reporting to the Board of Directors of the Company. You shall
have the responsibilities, duties and authority commensurate with the position
of President and Chief Scientific Officer, including, without limitation,
general supervision and control over, and responsibility for, the Company's
day-to-day operations, including research and development activities. In
addition to your primary duties, you shall perform such other services for the
Company as may be assigned to you from time to time by the Company. During the
term of your employment with the Company, you agree to serve as, and the Company
agrees to elect you, a member of the Board of Directors, with such
responsibilities, duties and authority as are customary to such position. You
shall devote your full time and best efforts in the performance of the foregoing
services. Notwithstanding the foregoing, at such time as the Company hires a
chief executive officer (the "CEO"), the Company may request that the CEO also
hold the office of President and, consequently, in the event that the Board of
Directors requests that you resign from the office of President, the Company
will continue your employment under this agreement in the capacities of (i)
Chief Scientific Officer of the Company and (ii) a second office of Executive
Vice President of Research & Development which is mutually agreeable to you and
the Company; provided that, (A) in any such event, upon the hiring of such CEO
you shall report to the CEO and (B) in the event that you and the Company
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mutually agree to such second office and you resign from the office of
President, you shall have the responsibilities, duties and authority
commensurate with such new position.

         2. Term of Employment. Your employment hereunder shall commence the
date of this Agreement (the "Commencement Date") and shall continue until the
third anniversary of the Commencement Date, provided that on the third
anniversary of the Commencement Date, and each anniversary thereafter, the term
of your employment hereunder shall be automatically extended for an additional
period of one (1) year unless either you or the Company shall have given written
notice to the other that such automatic extension not occur, which written
notice was given no later than sixty (60) days prior to the relevant anniversary
of the Commencement Date.

         3. Compensation; Equity; Benefits.

         (a) Salary. The Company shall pay you as your compensation for your
services and agreements hereunder during the term of this Agreement a base
salary at the rate of $150,000 per year (the "Base Salary"), payable in
substantially equal installments in accordance with the Company's payroll
practices for its senior executives as in effect from time to time, less any
amounts required to be withheld under applicable law. The Base Salary will be
increased from time to time in the sole discretion of the Board of Directors.

         (b) Signing Bonus. The Company will pay you a signing bonus of $50,000,
payable within thirty days following your execution of this Agreement.

         (c) Annual Bonus. The Company will pay you an incentive performance
bonus, anticipated to range from $30,000 to $60,000, which shall be determined
in good faith by the Board of Directors taking into consideration personal and
corporate achievement of established milestones.

         (d) Founder's Equity. Promptly following your execution of this
Agreement, the Company will issue and sell to you 300,000 shares of the
Company's Common Stock, representing not less than 20% of the Common Stock at
founding, at a purchase price equal to One-Tenth of One Cent ($.001) per share.
Of such 300,000 shares, 225,000 will be subject to the Company's right,
exercisable upon the termination or cessation of your employment, to repurchase
such shares at a repurchase price equal to One-Tenth of One Cent ($.001) per
share, and the Company's right to repurchase such shares will lapse in twelve
(12) equal quarterly installments ending on the third anniversary of the
Commencement Date.

         (e) Stock Options. The Company contemplates establishing a stock option
plan and awarding grants of stock options to certain employees. It is currently
contemplated that the Company will from time to time grant you options to
purchase, at fair market value, shares of Common Stock (i) in order that your
total equity position in the Company remains comparable to the equity positions
of similarly-situated executives at comparable companies and/or (ii) in order to
reward you for the achievement of specified milestones, such as the signing of a
large corporate partnership agreement, the completion of a large financing at a
significant increase in share price or the licensing of an important new
technology or compound.

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         (f) Vacation. You shall be entitled to vacation, paid holidays and
personal days in accordance with the Company's policies with respect to its
executives as in effect from time to time.

         (g) Fringe Benefits. You shall be entitled to participate in any
employee benefit plans which the Company provides or may establish for the
benefit of its employees, including medical, disability and dental plans and a
401(k) plan.

         (h) Reimbursement of Travel Expenses. You shall be entitled to
reimbursement for ordinary and reasonable out-of-pocket travel expenses which
are reasonably incurred by you in furtherance of the Company's business in
accordance with the Company's policies as in effect from time to time.

         (i) Reimbursement of Relocation Expenses. In connection with your
relocation from your current residence to a residence nearby the Company's
headquarters (currently anticipated to be in northern New Jersey), you shall be
entitled to reimbursement of the following expenses: (i) a broker's fee (not to
exceed 6%) incurred in connection with the sale of your current residence, (ii)
out-of-pocket legal expenses, and state and local taxes (if any), incurred by
you upon the sale of your current residence, (iii) ordinary packing and moving
expenses reasonably incurred by you, (iv) one percent (1%) of the purchase price
for your new residence, plus out-of-pocket costs incurred in connection with
such purchase, including as legal costs and the expenses of a home inspection
and (v) the cost of up to one (1) year of temporary housing; provided that you
shall obtain the Company's prior approval before incurring any of the foregoing
expenses. In addition, the Company will co-sign the mortgage on your current
residence, if required by the mortgage lender.

         4. Prohibited Competition.

         (a) Certain Acknowledgments and Agreements.

                  (i) You recognize and acknowledge the competitive and
         sometimes proprietary aspects of the business of the Company.

                  (ii) You acknowledge and agree that, for purposes of this
         Agreement, a business will be deemed competitive with the Company if it
         is engaged in the research, development or commercialization of agents
         to affect memory, cognitive abilities or any directly related
         neurological function.

         (b) Covenant Not to Compete. During the term of your employment with
the Company (the "Term") and for a period of one (1) year following the
expiration or termination of the Term, whether such termination is voluntary or
involuntary, you shall not, without the prior written consent of the Company:

                   (i) For yourself or on behalf of any other person or entity,
          directly or indirectly, either as principal, agent, stockholder,
          employee, consultant, representative or in any other capacity, own,
          manage, operate or control, or be concerned, connected or employed by,
          or otherwise associate in any manner with, engage in or have a
          financial interest in any business which is competitive with the
          business of the Company; provided that nothing contained herein shall
          preclude you from purchasing or owning securities of any such

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         business if (A) such securities are publicly traded (B) your holdings
         do not exceed three (3%) percent of the issued and outstanding
         securities of any class of securities of such business; or

                  (ii) Either individually or on behalf of or through any third
         party, solicit, divert or appropriate or attempt to solicit, divert or
         appropriate, for the purpose of competing with the Company or any
         present or future parent, subsidiary or other affiliate of the Company
         which is engaged in a similar business as the Company, any strategic
         partner, licensor, licensee, supplier or customer of the Company, or
         any prospective strategic partner, licensor, licensee, supplier or
         customer with respect to which the Company has developed or made a
         presentation or engaged in negotiations or discussions; or

                   (iii) Either individually or on behalf of or through any
         third party, directly or indirectly, solicit, entice or persuade or
         attempt to solicit, entice or persuade any other employees of or
         consultants to the Company or any present or future parent, subsidiary
         or affiliate of the Company to leave the services of the Company or any
         such parent, subsidiary or affiliate for any reason.

         (c) Reasonableness of Restrictions. You acknowledge that (i) the
restrictions in this Section 4 are reasonable in relation to your current and
future prospects for employment and (ii) the scope of this Section 4 is
reasonable, legitimate and fair to you in light of the Company's proprietary
needs and the restrictions on your future employment.

         (d) Survival of Acknowledgments and Agreements. Your acknowledgments
and agreements set forth in this Section 4 shall survive the expiration or
termination of this Agreement and the termination of your employment with the
Company for any reason for a period of one (1) year following such expiration or
termination.

         5. Protected Information. You shall at all times, both during and after
any termination of this Agreement by either you or the Company, maintain in
confidence and shall not, without the prior written consent of the Company, use,
except in the course of performance of your duties for the Company, disclose or
give to others any fact or information which was disclosed to or developed by
you during the course of performing services for the Company and is not
generally available to the public, including but not limited to information and
facts concerning business plans, customers, future customers, suppliers,
licensors, licensees, partners, investors, affiliates or others, training
methods and materials, financial information, sales prospects, client lists,
Inventions (as defined in Section 6), or any other scientific, technical, trade
or business secret or confidential or proprietary information of the Company or
of any third party provided to you during the Term. In the event you are
questioned by anyone not employed by the Company or by an employee of or a
consultant to the Company not authorized to receive such information, in regard
to any such information or any other secret or confidential work of the Company,
or concerning any fact or circumstance relating thereto, you will promptly
notify the Board of Directors of the Company.

         6. Ownership of Ideas, Copyrights and Patents.

         (a) Property of the Company. You agree that all ideas, discoveries,
creations, manuscripts and properties, innovations, improvements, know-how,
inventions, designs,

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developments, apparatus, techniques, methods, and formulae (all of the foregoing
being hereinafter referred to as "the Inventions") which may be used in the
business of the Company, whether patentable, copyrightable or not, which you may
conceive, reduce to practice or develop during the Term, alone or in conjunction
with another, or others, and whether at the request or upon the suggestion of
the Company, or otherwise, shall be the sole and exclusive property of the
Company, and that you shall not publish any of the Inventions without the prior
written consent of the Company. You hereby assign to the Company all of your
professional right, title and interest in and to all of the foregoing which is
so conceived, reduced to practice or developed during the Term. You further
represent and agree that to the best of your knowledge and belief none of the
Inventions will violate or infringe upon any right, patent, copyright, trademark
or right of privacy, or constitute libel or slander against or violate any other
rights of any person, firm or corporation and that you will use your best
efforts to prevent any such violation.

         (b) Cooperation. At any time during the Term and for a period of one
(1) year following the expiration or termination of the Term, you agree that you
will fully cooperate with the Company, its attorneys and agents in the
preparation and filing of all papers and other documents as may be required to
perfect the Company's rights in and to any of such Inventions, including, but
not limited to, joining in any proceeding to obtain letters patent, copyrights,
trademarks or other legal rights of the United States and of any and all other
countries on such inventions, provided that the Company will bear the expense of
such proceedings, and that any patent or other legal right so issued to you,
personally, shall be assigned by you to the Company without charge by you.

         7. Termination and Severance.

         (a) Termination. Notwithstanding anything in this Agreement to the
contrary, your employment hereunder shall be terminated upon the first to occur
of the following:

                  (i) Immediately upon your death;

                  (ii) By the Company by written notice sent to you effective as
         of the date of such notice:

                           (A) Following your failure, due to illness, accident
                  or any other physical or mental incapacity, to perform the
                  services provided for hereunder for an aggregate of ninety
                  (90) business days within any period of one hundred eighty
                  (180) consecutive business days during the term hereof
                  ("Permanent Disability");

                           (B) For Cause (as hereinafter defined); or

                           (C) Without Cause; or

                  (iii) By you at any time upon sixty (60) days prior written
         notice to the Company.

         (b) Definition of "Cause". For purposes of this Agreement, "Cause"
shall include (i) your conviction of a felony, either in connection with the
performance of your obligations to the


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Company or otherwise, which adversely affects your ability to perform such
obligations or materially adversely affects the business activities, reputation,
goodwill or image of the Company, (ii) your willful disloyalty, deliberate
dishonesty, breach of fiduciary duty or breach of the terms of this Agreement,
(iii) the commission by you of any act of fraud, embezzlement or deliberate
disregard of a rule or policy of the Company which results in loss, damage or
injury to the Company or (iv) the breach by you of any of the provisions of
Section 4,5 or 6 hereof.

         (c) Severance. In the event your employment shall be terminated by the
Company without Cause at any time or following your Permanent Disability, the
Company shall continue to pay you your Base Salary then in effect and the cost
of your health insurance for a period of one year following any such
termination; provided that the Company shall not be obligated to continue any
such payments in the event you breach the non-competition provisions contained
in Section 4(b). All payments made under this Section 7(c) shall be made at the
times and at the rate specified in Section 3(a) hereof.

         (d) No Severance. In the event your employment shall be terminated by
the Company for Cause, no further compensation or benefits of any kind shall be
payable to you hereunder (except for any health insurance benefits required by
applicable law); provided that you shall continue to be bound by the provisions
of this Agreement, other than Section 1.

         8. Disclosure to Future Employers. You agree that you will provide, and
that the Company may similarly provide in its discretion, a copy of the
covenants contained in Sections 4, 5 and 6 of this Agreement to any business or
enterprise which you may directly, or indirectly, own, manage, operate, finance,
join, control or in which you participate in the ownership, management,
operation, financing, or control, or with which you may be connected as an
officer, director, employee, partner, principal, agent, representative,
consultant or otherwise.

         9. Records. Upon termination of your relationship with the Company, you
shall deliver to the Company any property of the Company which may be in your
possession including products, materials, memoranda, notes, records, reports, or
other documents or photocopies of the same.

         10. Insurance. The Company, in its sole discretion, may apply for and
procure in its own name (whether or not for its own benefit) policies of
insurance insuring your life in such amounts as the Company deems advisable. You
shall have no right, title or interest in or to any such policies of insurance,
except as provided herein or to the extent your estate or other persons are
specifically named as beneficiaries thereof. You agree to submit to any medical
or other examinations and to execute and deliver any applications or other
instruments in writing that are reasonably necessary to effectuate such
insurance.

         11. No Conflicting Agreements. You hereby represent and warrant that
you have no commitments or obligations inconsistent with this Agreement and you
hereby agree to indemnify and hold the Company harmless against loss, damage,
liability or expense arising from any claim based upon circumstances alleged to
be inconsistent with such representation and warranty.

         12. General.


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         (a) Notices. All notices, requests, consents and other communications
hereunder shall be in writing, shall be addressed to the receiving party's
address set forth above or to such other address as a party may designate by
notice hereunder, and shall be either (i) delivered by hand, (ii) made by
telecopy or facsimile transmission, (iii) sent by overnight courier, or (iv)
sent by registered or certified mail, return receipt requested, postage prepaid.
All notices, requests, consents and other communications hereunder shall be
deemed to have been given either (i) if by hand, at the time of the delivery
thereof to the receiving party at the address of such party set forth above,
(ii) if made by telecopy or facsimile transmission, at the time that receipt
thereof has been acknowledged by electronic confirmation or otherwise, (iii) if
sent by overnight courier, on the next business day following the day such
notice is delivered to the courier service, or (iv) if sent by registered or
certified mail, on the fifth (5th) business day following the day such mailing
is made.

         (b) Entire Agreement. This Agreement embodies the entire agreement
understanding between the parties hereto with respect to the subject matter
hereof and supersedes all prior oral or written agreements and understandings
relating to the subject matter hereof. No statement, representation, warranty
covenant, or agreement of any kind not expressly set forth in this Agreement
shall affect, or be used to interpret, change or restrict, the express terms and
provisions of this Agreement.

         (c) Modifications and Amendments. The terms and provisions of this
Agreement may be modified or amended only by written agreement executed by the
parties hereto.

         (d) Waivers and Consents. The terms and provisions of this Agreement
may be waived, or consent for the departure therefrom granted, only by written
document executed by the party entitled to the benefits of such terms or
provisions. No such waiver or consent shall be deemed to be or shall constitute
a waiver or consent with respect to any other terms or provisions of this
Agreement, whether or not similar. Each such waiver or consent shall be
effective only in the specific instance and for the purpose for which it was
given, and shall not constitute a continuing waiver or consent.

         (e) Assignment. The Company may assign its rights and obligations
hereunder to any person or entity who succeeds to all or substantially all of
the Company's business or that aspect of the Company's business in which you are
principally involved. Your rights and obligations under this Agreement may not
be assigned by you without the prior written consent of the Company.

         (f) Benefit. All statements, representations, warranties, covenants and
agreements in this Agreement shall be binding on the parties hereto and shall
inure to the benefit of the respective successors and permitted assigns of each
party hereto. Nothing in this Agreement shall be construed to create any rights
or obligations except among the parties hereto, and no person or entity shall be
regarded as a third-party beneficiary of this Agreement.

         (g) Governing Law. This Agreement and the rights and obligations of the
parties hereunder shall be construed in accordance with and governed by the law
the Commonwealth of Massachusetts, without giving effect to the conflict of law
principles thereof.

         (h) Jurisdiction and Service of Process. Any legal action or proceeding
with respect to this Agreement shall be brought in the courts of the
Commonwealth of Massachusetts or of the


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United States of America for the District of Massachusetts. By execution and
delivery of this Agreement, each of the parties hereto accepts for itself and in
respect of its property, generally and unconditionally, the jurisdiction of the
aforesaid courts. Each of the parties hereto irrevocably consents to the service
of process of any of the aforementioned courts in any such action or proceeding
by the mailing of copies thereof by certified mail, postage prepaid, to the
party at its address set forth in Section 12(a) hereof.

         (i) Severability. The parties intend this Agreement to be enforced as
written. However, (i) if any portion or provision of this Agreement shall to any
extent be declared illegal or unenforceable by a duly authorized court having
jurisdiction, then the remainder of this Agreement, or the application of such
portion or provision in circumstances other than those as to which it is so
declared illegal or unenforceable, shall not be affected thereby, and each
portion and provision of this Agreement shall be valid and enforceable to the
fullest extent permitted by law; and (ii) if any provision, or part thereof, is
held to be unenforceable because of the duration of such provision or the
geographic area covered thereby, the Company and you agree that the court making
such determination shall have the power to reduce the duration and/or geographic
area of such provision, and/or to delete specific words and phrases
("blue-penciling"), and in its reduced or blue-penciled form such provision
shall then be enforceable and shall be enforced.

         (j) Headings and Captions. The headings and captions of the various
subdivisions of this Agreement are for convenience of reference only and shall
in no way modify, or affect the meaning or construction of any of the terms or
provisions hereof.

         (k) Injunctive Relief. You hereby expressly acknowledge that any breach
or threatened breach of any of the terms and/or conditions set forth in Section
4, 5 or 6 of this Agreement will result in substantial, continuing and
irreparable injury to the Company. Therefore, you hereby agree that, in addition
to any other remedy that may be available to the Company, the Company shall be
entitled to injunctive or other equitable relief by a court of appropriate
jurisdiction in the event of any breach or threatened breach of the terms of
Section 4, 5 or 6 of this Agreement.

         (l) Expenses. Should any party breach this Agreement, in addition to
all other remedies available at law or in equity, such party shall pay all of
any other party's costs and expenses resulting therefrom and/or incurred in
enforcing this Agreement, including legal fees and expenses.

         (m) Counterparts. This Agreement may be executed in one or more
counterparts, and by different parties hereto on separate counterparts, each of
which shall be deemed an original, but all of which together shall constitute
one and the same instrument.

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         If the foregoing accurately sets forth our agreement, please so
indicate by signing and returning to us the enclosed copy of this letter.

                                                 Very truly yours,

                                                 MEMORY PHARMACEUTICALS, INC.

                                                 By:    /s/ Jonathan J. Fleming
                                                        ------------------------
                                                 Name:  Jonathan J. Fleming
                                                 Title: Chairman of the Board

Accepted and Approved as of the date above:

/s/ Dr. Axel Unterbeck
---------------------------------------
Dr. Axel Unterbeck

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