L-2-THIENYLALANINE

Off-white crystals

3-(2-thienyl)-L-alanine, methylester hydrochloride A solution of 3-(2-thienyl)-L-alanine (200 mg, 1.17 mmol) in 3 mL of methanol was treated with chlorotrimethylsilane (0.73 mL, 5.84 mmol) and the mixture heated to reflux for 60 hours. The solution was then concentrated to provide 257 mg (99%) of the title compound. MS (DCI, NH3): 186 (MH+); 203 (M+NH4)+.The salt thus obtained was added with 210 mL of acetone, refluxed for 2 hr, and then cooled to room temperature, after which the deposited beta-2-thienyl-L-alanine was obtained (4.3 g, L/D ratio=96/4). The obtained beta-2-thienyl-L-alanine was analyzed using 1H-NMR. The results are as follows. 1H-NMR (D2O, 400 MHz): delta 2.99 (m, 2H), 3.33 (m, 1H), 6.76 (m, 1H), 6.85 (m, 1H), 7.13 (m, 1H)The salt thus obtained was added with 400 mL of acetone, refluxed for 3 hr, and then cooled to room temperature, after which the deposited 3-2-thienyl-L-alanine was obtained (LID ratio=82I18).(S)-2-amino-3-(thiophen-2-yl)propanoic acid 16a (400 mg, 2.33 mmol, prepared according to the known method of ") was dissolved in 10 mL of tert-butyl acetate. The mixture was cooled to 0C under argon atmosphere, and added dropwise with perchloric acid(352 mg(70%), 3.5 mmol). The reaction mixture was stirred at room temperature for 16 hours and then added with water, and adjusted to pH = 8'9 with saturated sodium bicarbonate solution and extracted with dichloromethane. The organic phases were combined, washed successively with water and saturated sodium chloride solution, dried over anhydrous sodium sulfate, filtered and the filtrate was concentrated under reduced pressure to obtain the crude title product of (S)-tert-butyl 2-amino-3-(thiophen-2-yl)propanoate 16b (370 mg, light yellow oil). The product was used in the next step without further purification. MS m/z (ESI): 228.3 [M+1].

Molecular Weight:171.22
XLogP3:-1.7
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:3
Exact Mass:171.03539970
Monoisotopic Mass:171.03539970
Topological Polar Surface Area:91.6
Heavy Atom Count:11
Complexity:151
Defined Atom Stereocenter Count:1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes