Abstract: The present invention relates to an improved process for the preparation of tritylated candesartan acid of formula (I) comprising a step of, reacting candesartan acid of formula (II) with trityl chloride in the presence of a base in a ketonic solvent.

Abstract: A process for the preparation of Irbesartan of formula (I) using the step of, reacting biphenyl derivative of formula (VIa) wherein R represents a group selected from —CONH2 or compound of formula wherein X represents H or C1-4 alkyl, preferably methyl; or any other such group which can be converted to cyano group, with 1-veleramido cyclopentane carboxylic acid of formula (V) in the presence of an acid in an organic solvent to give biphenyl derivative of formula (VIIa) wherein R has the same meaning as mentioned hereinabove.

Abstract: A process for the preparation of Irbesartan of formula (I) using the steps of: (i) reacting 4? aminomethyl-2-cyano biphenyl of formula (VI) with 1-veleramido cyclopentane carboxylic acid of formula (V) in an organic solvent and in the presence of an acid, without activating the —COOH group of compound of formula (V) to give 1-(2?cyanobiphenyl-4-yl-methylaminocarbonyl)-1-pentanoylamino cyclopentane of formula (VII). converting the compound of formula (VII) obtained in step (i) to Irbesartan of formula (I) by reacting the compound of the formula (VII) with tributyl tin azide in o-xylene to give Irbesartan of formula (I).

Abstract: Processes for the preparation of Venlafaxine (IX) via the novel epoxy-nitrile intermediate (I), which when subjected to hydrogenation forms compound (X), and may subsequently be reduced to yield the desired product (IX). The epoxy-nitrile intermediate (I) itself may be synthesized via various alternative reaction strategies, from a range of starting materials. E.g. 4-methoxy-benzaldehyde (VI), upon treatment with cyclohexyl magnesium bromide yields compound (V). This in turn may be oxidized to yield compound (III), which forms compound (II) on treatment with an (x-keto-halogenation agent. Cyanation of compound (II), then yields the desired epoxy nitrile intermediate (I), from which Venlafaxine (IX) may be synthesized.

Abstract: Processes for the preparation of Venlafaxine (IX) via the novel epoxy-nitrile intermediate (I), which when subjected to hydrogenation forms compound (X), and may subsequently be reduced to yield the desired product (IX). The epoxy-nitrile intermediate (I) itself may be synthesised via various alternative reaction strategies, from a range of starting materials. E.g. 4-methoxy-benzaldehyde (VI), upon treatment with cyclohexyl magnesium bromide yields compound (V). This in turn may be oxidised to yield compound (III), which forms compound (II) on treatment with an (x-keto-halogenation agent. Cyanation of compound (II), then yields the desired epoxy nitrile intermediate (I), from which Venlafaxine (IX) may be synthesised.