Quinisocaine

Quinisocaine (INN) or dimethisoquin (BAN and USAN) is a topical anesthetic used as an antipruritic.^[1]

Quinisocaine

Clinical data
AHFS/Drugs.com	International Drug Names
ATC code	D04AB05 (WHO)
Identifiers
IUPAC name 2-(3-Butylisoquinolin-1-yl)oxy-N,N-dimethyl-ethanamine
CAS Number	86-80-6 N
PubChem CID	6857
ChemSpider	6596 Y
UNII	772EN3BH6I
KEGG	D08462 Y
ChEMBL	ChEMBL127643 Y
CompTox Dashboard (EPA)	DTXSID8048525
ECHA InfoCard	100.001.546
Chemical and physical data
Formula	C17H24N2O
Molar mass	272.392 g·mol−1
3D model (JSmol)	Interactive image
SMILES O(c2nc(cc1ccccc12)CCCC)CCN(C)C
InChI InChI=1S/C17H24N2O/c1-4-5-9-15-13-14-8-6-7-10-16(14)17(18-15)20-12-11-19(2)3/h6-8,10,13H,4-5,9,11-12H2,1-3H3 Y Key:XNMYNYSCEJBRPZ-UHFFFAOYSA-N Y
NY (what is this?)  (verify)

Synthesis

Thieme Synthesis:^[2][3] Patent:^[4][5]

The Henry reaction between phthalaldehydic acid (2-Formylbenzoic acid) [119-67-5] (1) and 1-nitropentane [628-05-7] occurs by a mechanism that involves a hydroxy acid (2). Expulsion of water then gives (3). Reduction of the nitro group via catalytic hydrogenation leads to the amine, CID:158569430 (4). Treatment of that amine with sodium hydroxide leads to ring opening of the lactone ring to the intermediary amino acid (5). This cyclises spontaneously to the lactam so that the product isolated from the reaction mixture is in fact the isoquinoline derivative, CID:154188092 (7). Dehydration by means of strong acid gives 3-Butylisocarbostyril [132-90-1] (8). Phosphorus oxychloride converts the oxygen function to the corresponding chloride via the enol forms 3-butyl-1-chloroisoquinoline [87-06-9] (9). Displacement of halogen with the sodium salt from 2-dimethylaminoethanol (10) affords dimethisoquin (11).