Patent ID: 7371863

Claim:
A method of preparing 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol comprising the steps: a) reacting a compound of formula (2) with an alkylating agent of formula (3) wherein R 2 and R 3 are independently selected from H, C 1-12 alkyl, C 2-12 alkenyl, C 3-8 cycloalkyl, C 3-8 cycloalkenyl, acyl, aryl, or heteroaryl, optionally substituted with a C 1-12 alkyl, C 1-12 alkoxy, or aryl, and L is a leaving group, to obtain a quarternary salt of formula (4) wherein L, R 2 and R 3 are as defined above, b) reacting the quartemary salt of formula (4) with a mild reducing agent to obtain a compound of formula (5) wherein R 2 and R 3 are as defined above, c) reacting a compound of formula (5) with a reagent of formula (6a) wherein R′ is C 1-12 alkyl, C 2-12 alkenyl, C 3-8 cycloalkyl, C 3-8 cycloalkenyl, acyl, or aryl optionally substituted with one or more C 1-12 alkyl, C 1-12 alkoxy, or aryl, X is a leaving group, Y is O or S, Z is O, S or C 1-6 alkyl, optionally followed by reaction with a nucleophile, to obtain a mixture of a compound of formula (7a) and a compound of formula (7b) wherein Y, Z, and R′ are as defined above, d) reacting the mixture of (7a) and (7b) with a nucleophile, followed by acidification, to obtain a compound of formula (8a) wherein Y, Z, and R′ are as defined above, and c) reacting a compound of formula (8a) with an acid to obtain 4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol as an acid addition salt.