Title: Enalapril
CAS Registry Number: 75847-73-3
CAS Name: N-[(1S)-1-(Ethoxycarbonyl)-3-phenylpropyl]-L-alanyl-L-proline
Additional Names: 1-[N-[(S)-1-carboxy-3-phenylpropyl]-L-alanyl]-L-proline 1¢-ethyl ester
Molecular Formula: C20H28N2O5
Molecular Weight: 376.45
Percent Composition: C 63.81%, H 7.50%, N 7.44%, O 21.25%
Literature References: Angiotensin-converting enzyme (ACE) inhibitor; de-esterified in vivo to its active diacid metabolite, enalaprilat, q.v. Prepn: A. A. Patchett et al., Nature 288, 280 (1980); eidem, EP 12401; E. E. Harris et al., US 4374829 (1980, 1983 both to Merck & Co.). Pharmacology: D. M. Gross et al., J. Pharmacol. Exp. Ther. 216, 552 (1981); C. S. Sweet et al., ibid. 558. Bioavailability and metabolism: E. H. Ulm, Drug Metab. Rev. 14, 99 (1983). Comprehensive description: D. P. Ip, G. S. Brenner, Anal. Profiles Drug Subs. 16, 207-243 (1987). Clinical trial in congestive heart failure: Consensus Trial Study Group, N. Engl. J. Med. 316, 1429 (1987). Review of clinical experience in hypertension: H. J. Gomez et al., J. Cardiovasc. Pharmacol. 15, Suppl. 3, S26-S29 (1990); of clinical pharmacokinetics: R. J. MacFadyen et al., Clin. Pharmacokinet. 25, 274-282 (1993); of combination with hydrochlorothiazide: P. L. Malini, Adv. Ther. 10, 253-262 (1993).
Derivative Type: Maleate
CAS Registry Number: 76095-16-4
Manufacturers' Codes: MK-421
Trademarks: Amprace (Merck & Co.); Cardiovet (Intervet); Enacard (Merial); Enapren (Merck & Co.); Glioten (Armstrong); Hipoartel (Ipsen); Innovace (Merck & Co.); Naprilene (Sigma-Tau); Pres (Boehringer, Ing.); Renitec (Merck & Co.); Reniten (Merck & Co.); Renivace (Merck & Co.); Vasotec (Merck & Co.); Xanef (Merck & Co.)
Molecular Formula: C20H28N2O5.C4H4O4
Molecular Weight: 492.52
Percent Composition: C 58.53%, H 6.55%, N 5.69%, O 29.24%
Properties: White to off-white crystalline powder, mp 143-144.5°. Soly (g/ml): water 0.025; alcohol 0.08; methanol 0.20. [a]D25 -42.2° (c = 1 in methanol). pH (1% water) 2.6. pKa1 3.0; pKa2 (25°) 5.4.
Melting point: mp 143-144.5°
pKa: pKa1 3.0; pKa2 (25°) 5.4
Optical Rotation: [a]D25 -42.2° (c = 1 in methanol)
Derivative Type: Mixture of maleate with hydrochlorothiazide
Trademarks: Acesistem (Sigma-Tau); Co-Renitec (Merck & Co.); Enaloc (Leiras); Innozide (Merck & Co.); Lotrial D (Roemmers); Renacor (Merck & Co.); Vaseretic (Merck & Co.); Vasoretic (Merck & Co.); Xynertec (Merck & Co.)
Therap-Cat: Antihypertensive.
Therap-Cat-Vet: In treatment of heart failure in dogs.
Keywords: ACE-Inhibitor; Antihypertensive; N-Carboxyalkyl (peptide/lactam) Derivatives.
Enalaprilat Enallylpropymal Enanthotoxin Encainide Enciprazine

Enalapril VanDerVals transparent.png
Systematic (IUPAC) name
(2S)-1-[(2S)-2-{[(2S)-1-ethoxy-1-oxo-4-phenylbutan-2-yl]amino}propanoyl]pyrrolidine-2-carboxylic acid

(Diagrams above are enalapril and enalaprilat, respectively. Data below refers to enalapril unless indicated)
Clinical data
Trade names Vasotec
AHFS/Drugs.com monograph
MedlinePlus a686022
Pregnancy cat. C,D
Legal status Prescription only
Routes I.V. and P.O.
Pharmacokinetic data
Bioavailability 60% (oral)
Metabolism hepatic (to enalaprilat)
Half-life 11 hours (enalaprilat)
Excretion renal
CAS number 75847-73-3 YesY
ATC code C09AA02
PubChem CID 5388962
DrugBank DB00584
ChemSpider 4534998 YesY
KEGG D07892 YesY
Chemical data
Formula C20H28N2O5 
Mol. mass 376.447 g/mol
 YesY (what is this?)  (verify)
Enalapril 3D structure

Enalapril (marketed as Vasotec in the USA, Enaladex in some other countries, and Enacard for veterinary use[1]) is an angiotensin converting enzyme (ACE) inhibitor used in the treatment of hypertension, diabetic nephropathy, and some types of chronic heart failure. ACE converts the peptide hormone angiotensin I to angiotensin II. One of the actions of angiotensin II is the vasoconstriction of blood vessels resulting in an increase in blood pressure. ACE inhibitors such as enalapril prevent this effect. Enalapril has been shown to lower the death rate in systolic heart failure.[2] Enalapril was the first member of the group known as the dicarboxylate-containing ACE inhibitors.