US 12,358,871 B2
Photochemical synthesis of vitamin D3 using sensitizers
Anupama Datla, Thane (IN); Prashant Nagre, Thane (IN); Jagdish Tamore, Thane (IN); Sreenath Trivikram, Dombivli (IN); and Gajanan Degaonkar, Badlapur (IN)
Assigned to FERMENTA BIOTECH LIMITED, Thane (IN)
Appl. No. 17/608,931
Filed by FERMENTA BIOTECH LIMITED, Thane (IN)
PCT Filed May 5, 2020, PCT No. PCT/IN2020/050442
§ 371(c)(1), (2) Date Nov. 4, 2021,
PCT Pub. No. WO2020/230169, PCT Pub. Date Nov. 19, 2020.
Claims priority of application No. 201921019395 (IN), filed on May 15, 2019.
Prior Publication US 2022/0298106 A1, Sep. 22, 2022
Int. Cl. C07C 401/00 (2006.01)
CPC C07C 401/00 (2013.01) 20 Claims
 
1. A photochemical synthesis of vitamin D3 comprising:
a) irradiating 7-dehydrocholesterol (7-DHC) or a mixture of 7-DHC and a sterol precursor in the presence of a solvent and a photosensitizer of Formula (I):

OG Complex Work Unit Chemistry
wherein;
X is O or S;
R1 is a hydrogen atom or a C1-C5 alkyl group,
R2 and R3 each independently represent:
an unsubstituted or substituted aryl group,
an unsubstituted or substituted naphthyl group, or
an unsubstituted or substituted heteroaryl group having at least one heteroatom selected from the group consisting of N, O, and S;
to obtain a reaction mass containing crude Vitamin D3;
b) separating the crude Vitamin D3 from the reaction mass; and
c) purifying the crude vitamin D3 to obtain crystalline vitamin D3.