EXHIBIT 5


                                                               December 23, 1998


                                  ChiRex Inc.
                                  -----------
                       Registration Statement on Form S-3
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Dear Ladies and Gentlemen:

          We have acted as special counsel for ChiRex Inc., a Delaware
corporation (the "Company"), in connection with the filing by the Company with
the Securities and Exchange Commission (the "Commission") of a Registration
Statement on Form S-3 (the "Registration Statement") relating to (i) debt
securities of the Company, which may be senior (the "Senior Securities") or
subordinated (the "Subordinated Securities" and, collectively with the Senior
Securities, the "Debt Securities"); (ii) warrants to purchase Debt Securities
(the "Debt Warrants"); (iii) shares of preferred stock, $.01 par value per
share, of the Company (the "Preferred Stock"); (iv) warrants to purchase shares
of Preferred Stock (the "Preferred Stock Warrants"); (v) depositary shares
representing entitlement to all rights and preferences of fractional interests
in shares of Preferred Stock of a specified series (the "Depositary Shares");
(vi) Common Stock, $.01 par value per share, of the Company (the "Common
Stock"); and (vii) warrants to purchase shares of Common Stock (the "Common
Stock Warrants").  The Debt Warrants, Preferred Stock Warrants and the Common
Stock Warrants are referred to herein as the "Warrants", and the Debt
Securities, Preferred Stock, Depositary Shares, Common Stock and the Warrants
are referred to herein collectively as the "Offered Securities".  The Offered
Securities being registered under the Registration Statement will have an
aggregate initial offering price of up to $100,000,000, or the equivalent
thereof in foreign currencies or composite currencies and will be offered on a
continued or delayed basis pursuant to the provisions of Rule 415 under the
Securities Act of 1933, (the "Securities Act").

          Unless otherwise provided in any prospectus supplement forming a part
of the Registration Statement relating to a particular series of Debt
Securities, the Debt Securities will be issued under an Indenture in the form of
Exhibit 4.4 to the Registration Statement (the "Indenture") to be executed by
the Company and United States Trust Company of New York, as Trustee (the
"Trustee").  The Preferred Stock will be issued pursuant to a Certificate of
Designations (the "Certificate of Designations") relating to a particular series
of Preferred Stock.  The Depositary Shares will be issued under a Deposit
Agreement (the "Deposit Agreement") to be entered into between the Company and
an institution as identified in the Deposit Agreement. The Warrants will be
issued under one or more warrant agreements (each, a "Warrant Agreement"), each
to be entered into between the Company and one or more institutions as
identified in the applicable Warrant Agreement.

          In connection with the foregoing, we have examined originals, or
copies certified or otherwise identified to our satisfaction, of such documents,
corporate records and other instruments as we have deemed necessary for the
purposes of this opinion, including without limitation the following:  (a) the
Certificate of Incorporation, as amended of the Company; (b) the Amended and
Restated By-laws of the Company; (c) the Indenture; (d) the form of proposed
Deposit Agreement; (e) the form of proposed Warrant Agreement; (f) the form of
the Underwriting Agreement attached as Exhibit 1 to the Registration Statement;
and (g) the unanimous written consent of the Board of Directors of the Company.

          Based upon and subject to the foregoing and assuming that (i) the
Registration Statement and any amendments thereto (including post-effective
amendments) will have become effective and comply with all applicable laws; (ii)
the Registration Statement will be effective and will comply with all applicable
laws at the time the Offered Securities are offered or issued as contemplated by
the Registration Statement; (iii) a prospectus supplement will have been
prepared and filed with the Commission describing the Offered Securities offered
thereby and will comply with all applicable laws; (iv) all Offered Securities
will be issued and sold in compliance with applicable federal and state
securities laws and in the manner stated in the Registration Statement and the
appropriate prospectus supplement; (v) a definitive purchase, underwriting or
similar agreement and any other necessary agreement with

 
respect to any Offered Securities offered or issued will have been duly
authorized and validly executed and delivered by the Company and the other
parties thereto; and (vi) any Offered Securities issuable upon conversion,
exchange or exercise of any Offered Security being offered or issued will be
duly authorized, created and, if appropriate, reserved for issuance upon such
conversion, exchange or exercise, we are of the opinion as follows:

          (1)  The Company is duly incorporated and is a validly existing
     corporation under the laws of the State of Delaware.

          (2)  With respect to Debt Securities to be issued under the Indenture,
     when (A) the Trustee is qualified to act as Trustee under the Indenture,
     (B) the Trustee has duly executed and delivered the Indenture, (C) the
     Indenture has been duly authorized and validly executed and delivered by
     the Company to the Trustee, (D) the Indenture has been duly qualified under
     the Trust Indenture Act of 1939, as amended, (E) the Board of Directors of
     the Company or a duly constituted and acting committee thereof (such Board
     of Directors or committee being hereinafter referred to as the "Board") has
     taken all necessary corporate action to approve the issuance and terms of
     such Debt Securities, the terms of the offering thereof and related
     matters, and (F) such Debt Securities have been duly executed,
     authenticated, issued and delivered in accordance with the provisions of
     the Indenture, and the applicable definitive purchase, underwriting or
     similar agreement approved by the Board upon payment of the consideration
     therefor provided for therein, such Debt Securities will be validly issued
     and will constitute valid and binding obligations of the Company,
     enforceable against the Company in accordance with their terms, (subject to
     applicable bankruptcy, insolvency, reorganization, fraudulent conveyance,
     moratorium or other similar laws affecting creditors' rights generally from
     time to time in effect and subject to general principles of equity,
     regardless of whether considered in a proceeding in equity or at law).

          (3)  With respect to shares of Preferred Stock, when both (A) the
     Board has taken all necessary corporate action to approve the issuance and
     terms of the shares of Preferred Stock, the terms of the 
     


     offering thereof and related matters, including the adoption of a
     Certificate of Designation relating to such Preferred Stock and the filing
     of the Certificate of Designation with the Secretary of State of the State
     of Delaware, and (B) certificates representing the shares of Preferred
     Stock have been duly executed, countersigned, registered and delivered
     either (i) in accordance with the applicable definitive purchase,
     underwriting or similar agreement approved by the Board upon payment of the
     consideration therefor (not less than the par value of the Preferred Stock)
     provided for therein or (ii) upon conversion or exercise of any other
     Offered Security, in accordance with the terms of such Offered Security or
     the instrument governing such Offered Security providing for such
     conversion or exercise as approved by the Board, for the consideration
     approved by the Board (not less than the par value of the Preferred Stock),
     then the shares of Preferred Stock will be validly issued, fully paid and
     nonassessable.

          (4)  With respect to Depositary Shares, when (A) the Board has taken
     all necessary corporate action to approve the issuance and terms of the
     Depositary Shares, the terms of the offering thereof and related matters,
     including the adoption of a Certificate of Designation relating to the
     Preferred Stock underlying such Depositary Shares and the filing of the
     Certificate of Designation relating to the Preferred Stock underlying such
     Depositary Shares with the Secretary of State of the State of Delaware, (B)
     the Deposit Agreement or Agreements relating to the Depositary Shares and
     the related depositary receipts have been duly authorized and validly
     executed and delivered by the Company and the Depositary appointed by the
     Company, (C) the shares of Preferred Stock underlying such Depositary
     Shares have been deposited with a bank or trust company (which meets the
     requirements for the Depositary set forth in the Registration Statement)
     under the applicable Deposit Agreement, and (D) the depositary receipts
     representing the Depositary Shares have been duly executed, countersigned,
     registered and delivered in accordance with the appropriate Deposit
     Agreement and the applicable definitive purchase, underwriting or similar
     agreement approved by the Board upon payment of the 


     consideration therefor provided for therein, the Depositary Shares will be
     validly issued.

          (5)  With respect to shares of Common Stock, when both (A) the Board
     has taken all necessary corporate action to approve the issuance of and the
     terms of the offering of the shares of Common Stock and related matters and
     (B) certificates representing the shares of Common Stock have been duly
     executed, countersigned, registered and delivered either (i) in accordance
     with the applicable definitive purchase, underwriting or similar agreement
     approved by the Board upon payment of the consideration therefor (not less
     than the par value of the Common Stock) provided for therein or (ii) upon
     conversion or exercise of any other Offered Security, in accordance with
     the terms of such Offered Security or the instrument governing such Offered
     Security providing for such conversion or exercise as approved by the
     Board, for the consideration approved by the Board (not less than the par
     value of the Common Stock), then the shares of Common Stock will be validly
     issued, fully paid and nonassessable.

          (6)  With respect to the Warrants, when (A) the Board has taken all
     necessary corporate action to approve the creation of and the issuance and
     terms of the Warrants, the terms of the offering thereof and related
     matters, (B) the Warrant Agreement or Agreements relating to the Warrants
     have been duly authorized and validly executed and delivered by the Company
     and the warrant agent appointed by the Company and (C) the Warrants or
     certificates representing the Warrants have been duly executed,
     countersigned, registered and delivered in accordance with the appropriate
     Warrant Agreement or Agreements and the applicable definitive purchase,
     underwriting or similar agreement approved by the Board upon payment of the
     consideration therefor provided for therein, the Warrants will be validly
     issued.

          We are aware that we are referred to under the heading "Legal
Opinions" in the prospectus forming a part of the Registration Statement, and we
hereby consent to such use of our name therein and to the use of this opinion
for filing with the Registration Statement as Exhibit 5 thereto. In giving this
consent, we do not hereby admit that we are within the category of persons whose
consent is required under Section 7 of the Securities Act or the Rules and
Regulations of the Commission promulgated thereunder.


                                        Very truly yours,

                                        Cravath, Swaine & Moore

ChiRex Inc.
   300 Atlantic Street, Suite 402
      Stamford, CT 06901