4-chlorophenylalanine

Description

4-chlorophenylalanine · CAS 1991-78-2 · C9H10ClNO2. UNII R5J7E3L9SP. Melting Point: 238-240 °C; LogP: log Kow = -0.48; Dissociation Constants: pKa1 = 2.08.

Identification

CAS Registry Number	1991-78-2
PubChem CID	4652
Molecular formula	C9H10ClNO2
IUPAC name	2-amino-3-(4-chlorophenyl)propanoic acid
UNII (FDA)	R5J7E3L9SP

Computed Descriptors

Molecular Weight	199.63
XLogP3	-0.5
Hydrogen Bond Donor Count	2
Hydrogen Bond Acceptor Count	3
Rotatable Bond Count	3
Exact Mass	199.0400063
Monoisotopic Mass	199.0400063
Topological Polar Surface Area	63.3
Heavy Atom Count	13
Formal Charge	0

Physical & Chemical Properties

Melting Point	238-240 °C
LogP	log Kow = -0.48
Dissociation Constants	pKa1 = 2.08

Physical description & handling notes

• Crystals from methanol
• pKa1 = 2.17 (carboxylic acid); pKa2 = 9.11(amine)
• 144.46 Ų [M+H]+ [CCS Type: TW; Method: calibrated with polyalanine and drug standards]
• When heated to decomposition, it emits toxic fumes of NOx and Cl-

GHS Hazard Classification

Reported hazard statements	H301 (100%), H317 (100%)

Documented Uses

• Competitive inhibitor of the serotonin (5-HT) synthesis enzyme tryptophan hydroxylase
• ... The combined administration of phenylalanine (phe) and p-chlorophenylalanine (PCPA) /are models for/... research into the pathogenesis and treatment of PKU. ...
• Phenylalanine, 4-chloro-: INACTIVE
• Enzyme Inhibitors; Serotonin Antagonists
• The clinical and biochemical features of a patient with flushing and severe diarrhea due to the carcinoid syndrome are described. The patient had a paradoxical response to the tryptophan hydroxylase inhibitor parachlorophenylalanine with complete abolition of flushing and no effect on the diarrhea. Treatment with this drug was limited by adverse effects. /Former/
• ... When the 5-HT concentration in sexually deficient men is sufficiently decreased with parachlorophenylalanine (PCPA) treatment and testosterone levels increased following its administration, a vivid sexual stimulation appears in about half of the untractable cases. Similar results are observed by substituting testosterone with monoamine oxydase inhibitor (MAOI) in PCPA-treated volunteers. . ...

Synonyms

Fenclonine; 7424-00-2; 4-Chloro-DL-phenylalanine; 2-amino-3-(4-chlorophenyl)propanoic acid; 4-Chlorophenylalanine; Fenchlonine; Fenclonin; DL-p-Chlorophenylalanine; DL-PCPA; Fenclonina; DL-3-(p-Chlorophenyl)alanine; para-Chlorophenylalanine; Fencloninum; Alanine, 3-(4-chlorophenyl)-, DL-; CP-10188; CP-10,188

Frequently Asked Questions

What are the CAS number and molecular formula of 4-chlorophenylalanine?

CAS 1991-78-2; molecular formula C9H10ClNO2; molecular weight — g/mol.

What other names is 4-chlorophenylalanine known by?

Fenclonine, 7424-00-2, 4-Chloro-DL-phenylalanine, 2-amino-3-(4-chlorophenyl)propanoic acid, 4-Chlorophenylalanine, Fenchlonine.

Is 4-chlorophenylalanine classified as hazardous?

Hazard statements reported: H301, H317.

What are the key physical properties of 4-chlorophenylalanine?

Melting Point: 238-240 °C; LogP: log Kow = -0.48; Dissociation Constants: pKa1 = 2.08.

Facts on this page are taken from PubChem (US National Library of Medicine) and Wikidata. Grade-specific data — assay, moisture, particle size, packaging, shelf life — is issued per batch on the COA and is not published here.