Proficient Procedure for Preparation of Quinoline Derivatives Catalyzed by NbCl₅ in Glycerol as Green Solvent

Table 2

Effect of temperature and the amount catalyst on the synthesis of 2-quinoline derivatives via a condensation of 2-aminobenzophenone and 1,3-cyclohexadione in the presence of NbCl₅ in glycerol.

Entry	Catalyst (mmol)	Yield (%)
		r.t	60°C	80°C	110°C
1	None	—	10	15	33
2	0.01	15	20	25	52
3	0.05	25	40	56	78
4	0.1	55	76	88	98
5	0.2	60	78	90	98