<PAGE>
/------------------------------/
/ OMB APPROVAL /
/------------------------------/
/ OMB Number: 3235-0287 /
/ Expires: December 31, 2001 /
/ Estimated average burden /
/ hours per response...... 0.5 /
/------------------------------/
+--------+
| FORM 4 | U.S. SECURITIES AND EXCHANGE COMMISSION
+--------+ WASHINGTON, D.C. 20549
[_] Check this box if STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP
no longer subject
to Section 16. Filed pursuant to Section 16(a) of the Securities
Form 4 or Form 5 Exchange Act of 1934, Section 17(a) of the
obligations may Public Utility Holding Company Act of 1935 or
continue. See Section 30(f) of the Investment Company Act of 1940
Instruction 1(b).
(Print or Type Responses)
--------------------------------------------------------------------------------
1. Name and Address of Reporting Person*
Weist, Robert
--------------------------------------------------------------------------------
(Last) (First) (Middle)
1040 N. Lake Shore Drive, Unit 15D
--------------------------------------------------------------------------------
(Street)
Chicago, IL 60611
--------------------------------------------------------------------------------
(City) (State) (Zip)
--------------------------------------------------------------------------------
2. Issuer Name and Ticker or Trading Symbol
MediChem Life Sciences, Inc. (MCLS)
--------------------------------------------------------------------------------
3. IRS or Social Security Number of Reporting Person
(Voluntary)
--------------------------------------------------------------------------------
4. Statement for Month/Year
12/00
--------------------------------------------------------------------------------
5. If Amendment, Date of Original (Month/Year)
--------------------------------------------------------------------------------
6. Relationship of Reporting Person(s) to Issuer (Check all applicable)
X Director ___ Officer ___ 10% Owner ___ Other
--- (give title below) (specify below)
Member of Board of Directors
--------------------------------------------------------------------------------
7. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
---
___ Form filed by More than One Reporting Person
--------------------------------------------------------------------------------
Table I--Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
<TABLE>
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------------
1. Title 2. Trans- 3. Trans- 4. Securities Acquired (A) 5. Amount of 6. Owner- 7. Nature
of action action or Disposed of (D) Securities ship of In-
Security Date Code (Instr. 3, 4 and 5) Beneficially Form: direct
(Instr. 3) (Month/ (Instr. 8) Owned at Direct Bene-
Day/ ----------------------------------------------- End of (D) or ficial
Year) Month Indirect Owner-
Code V Amount (A) or Price (Instr. 3 and 4) (I) ship
(D) (Instr. 4) (Instr. 4)
------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C> <C>
------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------
</TABLE>
Reminder: Report on a separate line for each class of securities beneficially
owned directly or indirectly.
If the form is filed by more than one reporting person, see Instruction 4(b)(v).
Potential persons who are to respond to the collection of information contained
in this form are not required to respond unless the form displays a currently
valid OMB Number.
Page 2
SEC 1473 (7-97)
<PAGE>
FORM 4 (continued)
Table II--Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
<TABLE>
<CAPTION>
-----------------------------------------------------------------------------------------------------------------------------
1. Title of Derivative 2. Conver- 3. Trans- 4. Transac- 6. Number of Deriv-
Security (Instr. 3) sion or action tion Code ative Securities
Exercise Date (Instr. 8) Acquired (A) or
Price of (Month/ Disposed of (D)
Deriv- Day/ (Instr. 3, 4, and 5)
ative Year)
Security
---------------------------------------------------
Code V (A) (D)
-----------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C>
Employee Stock Option
(right to buy) $4.91 12/5/00 A 10,000
-----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------------------------------------------
<CAPTION>
------------------------------------------------------------------------------------------------------------------------------------
7. Date Exer- 8. Title and Amount of 8. Price 9. Number 10. Owner- 11. Na-
cisable and Underlying Securities of of Deriv- ship ture
Expiration (Instr. 3 and 4) Deriv- ative Form of In-
Date ative Secur- of De- direct
(Month/Day/ Secur- ities rivative Bene-
Year) ity Bene- Security: ficial
(Instr. ficially Direct Owner-
-------------------------------------------- 5) Owned (D) or ship
Date Expira- Amount or at End Indirect (Instr.
Exer- tion Title Number of of (I) 4)
cisable Date Shares Month (Instr. 4)
(Instr. 4)
------------------------------------------------------------------------------------------------------------------------------------
<S> <C> <C> <C> <C> <C> <C> <C> <C>
Employee
Stock
Option
(right to
12/5/00 12/5/10 buy) 10,000 10,000 D
------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------
------------------------------------------------------------------------------------------------------------------------------------
</TABLE>
Explanation of Responses:
/s/ Robert Weist 01/10/2001
------------------------------- -----------------
**Signature of Reporting Person Date
** Intentional misstatements or omissions of facts constitute Federal Criminal
Violations.
See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a)
Note: File three copies of this Form, one of which must be manually signed.
If space is insufficient, see Instruction 6 for procedure.
Potential persons who are to respond to the collection of information contained
in this form are not required to respond unless the form dsplays a currently
valid OMB Number.
Page 2
SEC 1473 (7-97)
