Hydrazine hydrate (1:1) → 2(3H)-Benzothiazolone, 4-methyl-, hydrazone

Temperature

140 °C

4-Methyl-2-dimethylaminobenzothiazole hydrobromide (10.95 g.; 0.04 mole), 85% hydrazine hydrate representing 8.01 g., 0.12 mole, and 33 ml. of ethylene glycol were mixed at room temperature and the mixture heated to 140°C. under nitrogen atmosphere. The reaction mixture was maintained at this temperature overnight. After 39 hours of reaction time, the reaction was cooled, diluted with 33 ml. of water, and filtered to separate the desired 4-methyl-2-hydrazinobenzothiazole compound. It was washed with water and dried 2 hours at 65°C. in vacuo, 5.43 g., 79% yield. The product was subjected to nmr, which showed about 5-10% of starting material. The melting point was 161°-166°C.

1. temperatureThe reaction mixture was maintained at this temperature overnight
2. customAfter 39 hours of reaction time
3. temperaturethe reaction was cooled
4. additiondiluted with 33 ml
5. filtrationof water, and filtered
6. customto separate the desired 4-methyl-2-hydrazinobenzothiazole compound
7. washIt was washed with water
8. customdried 2 hours at 65°C. in vacuo, 5.43 g

ORD record

ord-d39d2c1ba10e42ac849d96c47f6ab883

Source dataset

uspto-grants-1976_02

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US03937714