The 3-(Methylthio)propionic acid, with the cas registry number 646-01-5 and EINECS registry number 211-460-9, is also called 4-Thiapentanoic acid. And the molecular formula of the chemical is C₄H₈O₂S.

The characteristics of this chemical are as followings: (1)ACD/LogP: 0.58; (2)# of Rule of 5 Violations: 0; (3)ACD/LogD (pH 5.5): -0.66; (4)ACD/LogD (pH 7.4): -2.44; (5)ACD/BCF (pH 5.5): 1; (6)ACD/BCF (pH 7.4): 1; (7)ACD/KOC (pH 5.5): 2.86; (8)ACD/KOC (pH 7.4): 1; (9)#H bond acceptors: 2; (10)#H bond donors: 1; (11)#Freely Rotating Bonds: 3; (12)Polar Surface Area: 51.6 Å²; (13)Index of Refraction: 1.496; (14)Molar Refractivity: 30.14 cm³; (15)Molar Volume: 103.1 cm³; (16)Polarizability: 11.94×10^-24cm³; (17)Surface Tension: 42.7 dyne/cm; (18)Density: 1.164 g/cm³; (19)Flash Point: 104.5 °C; (20)Enthalpy of Vaporization: 53.56 kJ/mol; (21)Boiling Point: 249.2 °C at 760 mmHg; (22)Vapour Pressure: 0.00741 mmHg at 25°C.

Preparation of 3-(Methylthio)propionic acid: This chemical can be prepared by acrylic acid and dithiocarbonic acid S,S'-dimethyl ester. The reaction will need reagent 30% aq. KOH. The reaction time is 15 minutes with temperature of 25 - 70°C, and the yield is about 90%. 

Uses of 3-(Methylthio)propionic acid: It can react with diazomethane to produce 3-methylsulfanyl-propionic acid methyl ester. This reaction will need reagent methanol, the reaction temperature 4°C, and the yield is about 31%.  

You should be cautious while dealing with this chemical. It may cause burns. Therefore, you had better take the following instructions: Wear suitable protective clothing, gloves and eye/face protection, and if in case of contacting with eyes, rinse immediately with plenty of water and seek medical advice.

Addtionally, the following datas could be converted into the molecular structure:
(1)SMILES: O=C(O)CCSC
(2)InChI: InChI=1/C4H8O2S/c1-7-3-2-4(5)6/h2-3H2,1H3,(H,5,6)
(3)InChIKey: CAOMCZAIALVUPA-UHFFFAOYAJ