3-AMINO-4,5,6,7-TETRAHYDRO-BENZO[B]THIOPHENE-2-CARBOXYLIC ACID METHYL ESTER

3-AMINO-4,5,6,7-TETRAHYDRO-BENZO[B]THIOPHENE-2-CARBOXYLIC ACID METHYL ESTER Property

Melting point:

70-73 °C

Boiling point:

414.3±45.0 °C(Predicted)

Density 

1.273±0.06 g/cm3(Predicted)

storage temp. 

2-8°C(protect from light)

pka

2.24±0.20(Predicted)

Appearance

White to off-white Solid

Hazard and Precautionary Statements (GHS)

Symbol(GHS)

Signal word

Warning

Hazard statements

H315Causes skin irritation

H319Causes serious eye irritation

H335May cause respiratory irritation

Precautionary statements

P261Avoid breathing dust/fume/gas/mist/vapours/spray.

P264Wash hands thoroughly after handling.

P264Wash skin thouroughly after handling.

P271Use only outdoors or in a well-ventilated area.

P280Wear protective gloves/protective clothing/eye protection/face protection.

P302+P352IF ON SKIN: wash with plenty of soap and water.

P304+P340IF INHALED: Remove victim to fresh air and Keep at rest in a position comfortable for breathing.

P305+P351+P338IF IN EYES: Rinse cautiously with water for several minutes. Remove contact lenses, if present and easy to do. Continuerinsing.

P312Call a POISON CENTER or doctor/physician if you feel unwell.

P321Specific treatment (see … on this label).

P332+P313IF SKIN irritation occurs: Get medical advice/attention.

P337+P313IF eye irritation persists: Get medical advice/attention.

P362Take off contaminated clothing and wash before reuse.

P403+P233Store in a well-ventilated place. Keep container tightly closed.

P405Store locked up.

P501Dispose of contents/container to..…

3-AMINO-4,5,6,7-TETRAHYDRO-BENZO[B]THIOPHENE-2-CARBOXYLIC ACID METHYL ESTER Chemical Properties,Usage,Production

Synthesis

Ethyl methyl-S-(2-cyanocyclohex-1-enyl)sulfonate (9) (0.17 g, 0.78 mmol) was used as the starting material and it was mixed with freshly distilled anhydrous THF (3 mL). Potassium tert-butoxide (0.09 g, 0.78 mmol) was subsequently added and the reaction mixture was heated to reflux for 30 min. The reaction progress was monitored by thin layer chromatography (TLC) (eluent: petroleum ether/ethyl acetate, 5:1). After completion of the reaction, the mixture was concentrated under reduced pressure, dissolved by addition of dichloromethane (25 mL) and washed with distilled water (2 x 20 mL), and the organic phase was dried over anhydrous magnesium sulfate. After evaporation of the solvent, the resulting oil was dried under high vacuum (10^-1 mbar). After refrigeration overnight, the light yellow solid product methyl 3-amino-4,5,6,7-tetrahydrobenzo[b]thiophene-2-carboxylate (135 mg, 80% yield) was obtained. The product was characterized as follows: melting point 70-73 °C; 1H NMR (CDCl3) δ: 1.82 (m, 4H, H5, H6), 2.30 (m, 2H, H7), 2.67 (m, 2H, H4), 3.79 (s, 3H, COOCH3), 5.36 (br s, 2H, NH2); 13C NMR (CDCl3) δ. 21.9, 22.6 (2CH2, C5, C6), 23.1 (CH2, C4), 25.8 (CH2, C7), 51.1 (COOCH3), 97.3 (CAr), 126.2 (CAr), 143.5 (CAr), 152.6 (CAr), 165.4 (COOCH3); IR (KBr) ν: 768 , 1072, 1095, 1130, 1198, 1263, 1300, 1342, 1448, 1493, 1568, 1604, 1668, 1734 (ester), 2858, 2933, 3361 (NH2), 3464 (NH2) cm^-1 ; MS (EI, 70 eV) m/z (%): 32 ( 80), 40 (10), 45 (10), 65 (10), 77 (15), 91 (15), 118 (15), 151 (65), 179 (90), 211 (M+, 100), 212 (M+H+, 10); HRMS-FAB: m/z [M+H]+ calcd for C10H13NO2S. 211.0667; found: 211.0745.

References

[1] Tetrahedron Letters, 2011, vol. 52, # 3, p. 401 - 403