Patent ID: 7405319

Claim:
An improved process for the preparation of carbamates, which comprises reacting amine and alkyl halide in presence of an ordered, bi-functional mesoporous silica catalyst with a molar composition of: X Mo 2 . (1 −x ) SiO 2 .y B wherein B is adenine, M is Ti 4+ ions, x lies between 0.0095 and 0.025 moles; y varies between 0.054 and 0.12 moles, and wherein said reacting is in an autoclave, under CO 2 pressure of about 3.4 bar, at a temperature of about 80° C., for a period of about 4 hours cooling the above said reaction mixture to a temperature of about 25° C. and removing the unreacted CO 2 , followed by the separation of the catalyst by filtration to obtain the desired product.