Hydrazine hydrate (1:1) → 2-Amino-5-nitrobenzenethiol

Temperature

25 °C

A solution of 6-nitrobenzothiazole (5 g, 27.7 mmol) in ethanol (50 mL) was treated with mono hydrazine hydrate (19 g, 388 mmol). The reaction mixture was stirred for 3 h at 25° C. and concentrated in vacuo. The resulting red oil was taken up in ethyl acetate, carefully acidified with 0.1 M aqueous hydrochloric acid solution until the solution turned light yellow. The reaction mixture was extracted with ethyl acetate, dried over magnesium sulfate, filtered, and concentrated in vacuo. The resulting orange solid was triturated with diethyl ether and dried in vacuo to afford the desired product, 2-amino-5-nitro-benzenethiol (4.1 g, 23.9 mmol, 86% yield) as a yellow solid. 1H NMR (400 MHz, Acetone-d6) δ 6.43 (bs, 2H), 6.82 (d, 1H, J=8.7 Hz), 7.65 (d, 1H, J=2.2 Hz), 7.88 (dd, 1H, J1=8.9 Hz, J2=2.7 Hz). LC-MS (ESI) calcd for C6H6N2O2S [M+H+] 171.01, found 193.20 [M+Na+].

1. concentrationconcentrated in vacuo
2. extractionThe reaction mixture was extracted with ethyl acetate
3. dry with materialdried over magnesium sulfate
4. filtrationfiltered
5. concentrationconcentrated in vacuo
6. customThe resulting orange solid was triturated with diethyl ether
7. customdried in vacuo

ORD record

ord-78a0469581eb4a0f80fecc3f22fd8af0

Source dataset

uspto-grants-2009_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07582754B2