English to Spanish Medical Law: Patents, Trademarks, Copyright chemical file

CLAIMS
We claim:

1. A method for preparing a compound of formula II:

II
wherein
R1 is alkyl, alkanoyl, aroyl, carboalkoxy, or carboalkoxyaryl;
R2 and R3 are, independently, hydrogen, hydroxy, alkyl, alkoxy, halogen, carboxamido, carboalkoxy, perfluoroalkyl, cyano, alkanesulfonamido, alkanesulfonyl, alkanamido, amino, alkylamino, dialkylamino, perfluoroalkoxy, alkanoyloxy, alkanoyl, aroyl, aryl, arylalkyl, heteroaryl, or heteroarylalkyl;
R6 and R7 are, independently, hydrogen or alkyl;
n is 1 or 2;
R4 and R5 are, independently, hydrogen or alkyl or, taken together with the carbons to which they are attached, form a cyclic moiety that is cycloalkyl, cycloalkenyl, bridged bicyclic alkyl, bridged bicyclic alkenyl, pyranyl or thiopyranyl in which the sulfur atom is optionally oxidized to the sulfoxide or sulfone; and
the dotted line represents an optional double bond,
which comprises reacting a compound of formula I:

I
wherein:
n, R1, R2, R3, R6 and R7 are as defined above,
with at least one formaldehyde equivalent and a reagent having either formula R4-CH=CH-R5 or formula R4-CºC-R5, wherein R4 and R5 are as defined herein, in the presence of a Lewis acid and a reaction solvent to form a compound of formula II, providing that the formaldehyde equivalent is in solid form at least prior to the reaction.

2. The method of claim 1 wherein the formaldehyde equivalent comprises paraformaldehyde.