IUPAC Name: 1-[10-[1-(dimethylamino)propan-2-yl]phenothiazin-3-yl]propan-1-one hydrochloride 
Molecular Formula C₂₀H₂₅ClN₂OS
Molecular Weight 376.9433g/mol
H-Bond Donor: 1
H-Bond Acceptor: 3
Rotatable Bond Count: 5
Tautomer Count: 2
Exact Mass: 376.137612
MonoIsotopic Mass: 376.137612
Topological Polar Surface Area: 23.6
Heavy Atom Count: 25
Formal Charge: 0
Complexity: 441 
Flash Point: 256.5 °C
Enthalpy of Vaporization: 76.91 kJ/mol
Boiling Point: 500.5 °C at 760 mmHg
Vapour Pressure: 3.78E-10 mmHg at 25°C
Canonical SMILES: CCC(=O)C1=CC2=C(C=C1)N(C3=CC=CC=C3S2)C(C)CN(C)C.Cl
InChI: InChI=1S/C20H24N2OS.ClH/c1-5-18(23)15-10-11-17-20(12-15)24-19-9-7-6-8-16(19)22(17)14(2)13-21(3)4;/h6-12,14H,5,13H2,1-4H3;1H
InChIKey: BXSAUVGIPSJAOJ-UHFFFAOYSA-N
Structure of Propiomazine hydrochloride (CAS NO.64-89-1):
 

 Propiomazine is an antihistamine. It is used to treat insomnia, and to relieve anxiety before or during surgery or other procedures, and to produce sleepiness or drowsiness and in combination with analgetics also during labor. Propiomazine is a phenothiazine, but is not used as a neuroleptic because it does not do a good job of blocking dopamine receptors.

Poison by intravenous and intramuscular routes. Moderately toxic by skin contact. When heated to decomposition it emits very toxic fumes of SO_x, NO_x, and HCl.

  Propiomazine hydrochloride its cas register number is 64-89-1. It also can be called 1-(10-(2-(Dimethylamino)-1-methylethyl)phenothiazin-2-yl)-1-propanone hydrochloride ; Largon hydrochloride ;Propiomazine hydrochloride . When heated to decomposition it emits very toxic fumes of SO_x, NO_x, and HCl. Propiomazine hydrochloride (CAS NO.64-89-1) is moderately toxic by skin contact. So Wear suitable protective clothing and gloves when contact with it. In addition, 
 Propiomazine is an antihistamine. serious side effects of it  include convulsions; difficult or unusually fast breathing; fast or irregular heartbeat or pulse; fever; high or low blood pressure; loss of bladder control; muscle stiffness; unusual increase in sweating; unusually pale skin; and unusual tiredness or weakness.