105-20-4 Usage
Originator
Histalog,Lilly,US,1953
Definition
ChEBI: Pyrazole in which a hydrogen adjacent to one of the nitrogen atoms is substituted by a 2-aminoethyl group. It is a histamine H2-receptor agonist used clinically to test gastric secretory function.
Manufacturing Process
A solution of 55 grams (1.1 mol) of hydrazine hydrate in 100 ml of methanol
was cooled in a water bath and stirred while a solution of 48 grams (0.50
mol) of pure γ-pyrone in 100 ml of methanol was added over a period of
about 15 minutes. After the addition was complete, the solution was allowed
to stand at room temperature for about 1 hour, and was placed in a 1 liter
hydrogenation bomb. 25 ml of liquid ammonia were added cautiously with
stirring, followed by about 15 cc of Raney nickel catalyst. The bomb was
charged with hydrogen to 1,800 pounds pressure, heated to 90°C and
agitated. The quantity of hydrogen required to convert the hydrazone into the
desired aminoethylpyrazole was taken up in about 3 hours. The bomb was
cooled and opened, and the contents filtered. The filtrate was evaporated
under reduced pressure to remove the methanol and the residual liquid was
distilled under reduced pressure, whereby there were obtained 44.5 grams
(81% yield) of 3-β-aminoethylpyrazole boiling at 118°-123°C at a pressure of
0.5 mm of Hg.
Brand name
Histalog (Lilly).
Therapeutic Function
Diagnostic aid (gastric secretion)
Check Digit Verification of cas no
The CAS Registry Mumber 105-20-4 includes 6 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 3 digits, 1,0 and 5 respectively; the second part has 2 digits, 2 and 0 respectively.
Calculate Digit Verification of CAS Registry Number 105-20:
(5*1)+(4*0)+(3*5)+(2*2)+(1*0)=24
24 % 10 = 4
So 105-20-4 is a valid CAS Registry Number.
InChI:InChI=1/C5H9N3/c6-3-1-5-2-4-7-8-5/h2,4H,1,3,6H2,(H,7,8)
105-20-4Relevant articles and documents
Biocatalytic access to betazole using a one-pot multienzymatic system in continuous flow
Paradisi, Francesca,Romero-Fernandez, Maria
, p. 4594 - 4603 (2021)
As an alternative to classical synthetic approaches for the production of betazole drug, a one-pot biocatalytic system for this pharmaceutical molecule from its alcohol precursor has been developed. An ω-transaminase, an alcohol dehydrogenase and a water-forming NADH oxidase forin situcofactor recycling have been combined to catalyse this reaction, yielding 75% molar conversion in batch reactions with soluble enzymes. This multienzyme system was then co-immobilised through a newly established protocol for sequential functionalization of a methacrylate-based porous carrier to enable tailored immobilisation chemistries for each enzyme. This pluri-catalytic system has been set up in a continuous flow packed-bed reactor, generating a space-time yield of up to 2.59 g L?1h?1with 15 min residence and a constant supply of oxygen forin situcofactor recycling through a segmented air-liquid flow. The addition of an in-line catch-and-release column afforded >80% product recovery.
