2-Amino-6-phthalimido-4,5,6,7-tetrahydro benzothiazole synthesis
- Product Name:2-Amino-6-phthalimido-4,5,6,7-tetrahydro benzothiazole
- CAS Number:104618-33-9
- Molecular formula:C15H13N3O2S
- Molecular Weight:299.35
Yield:-
Reaction Conditions:
with bromine in ethanol at 5 - 78; for 8 h;
Steps:
1.B
Preparation of 2-amino-6-phthalimido-4,5,6,7-tetrahydrobenzothiazole via 4-(phthalimido)-cyclohexanone; 1.0 Kg of 4-(phthalimido)-cyclohexanol was added in 20.0 L of acetone at 250C to 350C. The reaction mixture was cooled to 50C to 100C and treated with chromic acid solution. 0.2 L of isopropanol was added and stirred for 30 min. The reaction mixture was filtered and washed with acetone (1.0 L). The filtrate was treated with 0.4 kg sodium bicarbonate at 250C to 350C and stirred for 1 h. The reaction mass was again filtered, washed with acetone (1.0 L). Excess of acetone was distilled under vacuum. The residue was treated with 0.5 L ethanol followed by distillation of ethanol under vacuum. The reaction mass was cooled and treated with 3.36 L ethanol at 450C to 250C while gradual cooling. The reaction mixture was further cooled to 150C to 200C and treated with 0.22 L of bromine and 0.43 Kg of thiourea under stirring for 1 h. The reaction mixture was heated to reflux at 750C to 780C for 6 hrs. The reaction mixture was cooled and stirred for 1 hr at 50C to 100C. The product was isolated by centrifuge, washing with ethanol 0.66 L and drying under vacuum at 500C to 550C. (yield: 0.70 Kg).
References:
CADILA HEALTHCARE LIMITED WO2008/41240, 2008, A1 Location in patent:Page/Page column 16-17
