Water → HCID 19880924, compound

Participants

Reaction Conditions

Reaction Steps

10 g (38.5 mmol) of 7-chloro-1,3-dihydro-5-(1H-pyrrol-2-yl)-1,4-benzodiazepin-2-one were dissolved in anhydrous THF (400 ml) in a 1 litre round-bottom 3-neck flask equipped with a mechanical stirrer. The flask was then placed in the water bath of an ultrasonic apparatus. To the stirred reaction solution was added P4S10 (10 g; 22.5 mmol) and the reaction mixture was irradiated with ultrasound. The temperature was maintained at about 40° C. throughout the reaction. After 2.5 hours, an additional portion of P4S10 (10 g; 22.5 mmol) was added to the mixture and the reaction was continued for an additional 2 hours. The heterogeneous mixture was cooled to ambient temperature and filtered. After washing the solid by-product with several portions of CH2CL2, the filtrates were combined and approximately 80% of the solvent was removed in vacuo. The residual solution was basified with saturated sodium bicarbonate solution until a pH of about 8 was reached. The product which precipitated out was filtered. The filtrate was then extracted with CH2Cl2, followed by concentration in vacuo. The solids were combined and recrystallized in THF/Petroleum ether to give 9.9 g (94% yield) of 7-chloro-1,3-dihydro-5-(1H-pyrrol-2yl)-1,4-benzodiazepin-2-thione as a pale yellow powder having the following characteristics: m.p. 258°-260° C. dec.; IR (KBr) 3450, 3165 cm-1. Anal. Calcd. for C13H10C1N3S: C 56.62; H 3.66; N 15.24. Found: C 56.50; H 3.59; N 15.12.

Provenance & Evidence