Exhibit
99.6


 


AMENDMENT
No. 1


 


To


 


8%
FIXED PROMISSORY NOTE


 


This
Amendment No. 1 to 8% Fixed Promissory Note (this “Amendment”) is dated September 30, 2020 (the “Effective
Date”), and is made by and among RespireRx Pharmaceuticals Inc., a Delaware corporation (the “Company”)
and White Lion Capital LLC, a Nevada limited liability company (the “Investor”).


 


WHEREAS,
Company and Investor (collectively, the “Parties”) are parties to that certain 8% Fixed Promissory Note,
dated July 28, 2020 (the “Note”); and


 


WHEREAS,
the Parties desire to amend the Note to increase the principal amount by $15,000 from $25,000 to $40,000.


 


NOW,
THEREFORE, in consideration of the mutual covenants and promises contained in the Note and this Amendment and other good and
valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties agree as follows:


 


1.
Amendments


 


(a)
The heading of the Note, which currently reads “Principal Amount: $25,000” is hereby amended and restated
in its entirety to read as follows:


 


“Principal
Amount: $40,000”


 


(b)
The second paragraph of the prefatory language of the Note, which currently reads “This
Note is a duly authorized Fixed Promissory Note of RespireRx Pharmaceuticals Inc. (the “Company”),
designated as the Company’s 8% Fixed Promissory Note due July 28, 2021 (“Maturity Date”) in the
principal amount of $25,000 (the “Note”)” is hereby amended and restated in its entirety to read as
follows:


 


“This
Note is a duly authorized Fixed Promissory Note of RespireRx Pharmaceuticals Inc. (the “Company”), designated
as the Company’s 8% Fixed Promissory Note due July 28, 2021 (“Maturity Date”) in the principal amount
of $40,000 (the “Note”)”


 


(c)
The definition of the term “Principal Sum” in the definitions section of the Note is hereby amended and
restated in its entirety to read as follows:


 


““Principal
Sum” shall mean the original principal amount of this Note of $40,000 as reduced by any conversions.”


 




    	 



     


    

 


(d)
The parenthetical in the first line of the Form of Conversion Notice attached as Exhibit A to the Note (the
“Notice”) is hereby amended and restated in its entirety to read as follows:


 


“(To
be executed by the Holder in order to convert all or part of that certain 8% $40,000 Fixed Promissory Note identified as the Note)”


 


(e)
The subject line of the Notice is hereby amended and restated in its entirety to read as follows:


 


“Re:
8% $40,000 Fixed Promissory Note (this “Note”) originally issued by RespireRx Pharmaceuticals, Inc., a Delaware corporation,
to White Lion Capital on July 28, 2020.”


 


2. Timing
of Payment. For the purposes of Rule 144 under the Securities Act of 1933, as amended, the Company acknowledges that
it issued to the Investor, for value received, $25,000 of the Principal Amount on July 28, 2020, and that it issued to the
Investor, for value received, $15,000 of the Principal Amount on the date of this Amendment.


 


3. Miscellaneous.


 


(a) Effect
of this Amendment. Except as amended hereby, the existing Note is in all respects ratified and confirmed, and all of the
terms, provisions and conditions thereof shall be and remain in full force and effect and are hereby incorporated by
reference, except as modified, amended and/or restated as set forth herein. In the event of any inconsistency or conflict
between the provisions of the Note and this Amendment, the provisions of this Amendment will prevail and govern. All
references to the existing Note shall hereinafter refer to the existing Note as amended by this Amendment.


 


(b)
Governing Law. This Amendment Agreement, and the rights and obligations of the parties hereunder, will be
governed, construed and interpreted in accordance with the laws of the State of Delaware, without giving effect to principles
of conflicts of law.


 


(c) Entire
Agreement. This Amendment and the Note constitute the entire agreement of the Parties with respect to the subject matter
hereof and supersede all prior understandings and writings between the Parties relating thereto.


 


(d) Further
Assurances. The parties agree to execute such further documents and instruments and to take such further actions as may
be reasonably necessary to carry out the purposes and intent of this Amendment.


 


(e) Counterparts.
This Amendment may be executed in counterparts and delivered by facsimile or any similar electronic transmission device, each
of which shall be deemed an original, but all of which shall be considered one and the same agreement.


 


[Signature
page follows]


 




    	-2-



     


    

 


IN
WITNESS WHEREOF, the Company has duly executed this Amendment to the Note as of the day and in the year first above written.


 


	 	RESPIRERX
    PHARMACEUTICALS INC.
	 	 	 
	 	By:	/s/
    Jeff E. Margolis            
	 	Name:	Jeff
    E. Margolis
	 	Title:	Senior
    Vice President, Chief Financial Officer, Treasurer and Secretary


 


	Agreed
    and Accepted:	 
	 	 
	WHITE
    LION CAPITAL LLC	 
	 	 	 
	By:	/s/
    Yash Thukral	 
	Name:	Yash
    Thukral	 
	Title:	Managing
    Member	 


 


[Signature
Page to 2020 Note Amendment]